U.S. flag

An official website of the United States government

The .gov means it's official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

  • Publications
  • Account settings
  • Browse Titles

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-.

Cover of StatPearls

StatPearls [Internet].

Delivery, face and brow presentation.

Julija Makajeva ; Mohsina Ashraf .

Affiliations

Last Update: January 9, 2023 .

  • Continuing Education Activity

Face and brow presentation is a malpresentation during labor when the presenting part is either the face or, in the case of brow presentation, it is the area between the orbital ridge and the anterior fontanelle. This activity reviews the evaluation and management of these two presentations and explains the role of the interprofessional team in managing delivery safely for both the mother and the baby.

  • Describe the mechanism of labor in the face and brow presentation.
  • Summarize potential maternal and fetal complications during the face and brow presentations.
  • Review different management approaches for the face and brow presentation.
  • Outline some interprofessional strategies that will improve patient outcomes in delivery cases with face and brow presentation issues.
  • Introduction

The term presentation describes the leading part of the fetus or the anatomical structure closest to the maternal pelvic inlet during labor. The presentation can roughly be divided into the following classifications: cephalic, breech, shoulder, and compound. Cephalic presentation is the most common and can be further subclassified as vertex, sinciput, brow, face, and chin. The most common presentation in term labor is the vertex, where the fetal neck is flexed to the chin, minimizing the head circumference.

Face presentation – an abnormal form of cephalic presentation where the presenting part is mentum. This typically occurs because of hyperextension of the neck and the occiput touching the fetal back. Incidence of face presentation is rare, accounting for approximately 1 in 600 of all presentations. [1] [2] [3]

In brow presentation, the neck is not extended as much as in face presentation, and the leading part is the area between the anterior fontanelle and the orbital ridges. Brow presentation is considered the rarest of all malpresentation with a prevalence of 1 in 500 to 1 in 4000 deliveries. [3]

Both face and brow presentations occur due to extension of the fetal neck instead of flexion; therefore, conditions that would lead to hyperextension or prevent flexion of the fetal neck can all contribute to face or brow presentation. These risk factors may be related to either the mother or the fetus. Maternal risk factors are preterm delivery, contracted maternal pelvis, platypelloid pelvis, multiparity, previous cesarean section, black race. Fetal risk factors include anencephaly, multiple loops of cord around the neck, masses of the neck, macrosomia, polyhydramnios. [2] [4] [5]

These malpresentations are usually diagnosed during the second stage of labor when performing a digital examination. It is possible to palpate orbital ridges, nose, malar eminences, mentum, mouth, gums, and chin in face presentation. Based on the position of the chin, face presentation can be further divided into mentum anterior, posterior, or transverse. In brow presentation, anterior fontanelle and face can be palpated except for the mouth and the chin. Brow presentation can then be further described based on the position of the anterior fontanelle as frontal anterior, posterior, or transverse.

Diagnosing the exact presentation can be challenging, and face presentation may be misdiagnosed as frank breech. To avoid any confusion, a bedside ultrasound scan can be performed. [6]  The ultrasound imaging can show a reduced angle between the occiput and the spine or, the chin is separated from the chest. However, ultrasound does not provide much predicting value in the outcome of the labor. [7]

  • Anatomy and Physiology

Before discussing the mechanism of labor in the face or brow presentation, it is crucial to highlight some anatomical landmarks and their measurements. 

Planes and Diameters of the Pelvis

The three most important planes in the female pelvis are the pelvic inlet, mid pelvis, and pelvic outlet. 

Four diameters can describe the pelvic inlet: anteroposterior, transverse, and two obliques. Furthermore, based on the different landmarks on the pelvic inlet, there are three different anteroposterior diameters, named conjugates: true conjugate, obstetrical conjugate, and diagonal conjugate. Only the latter can be measured directly during the obstetric examination. The shortest of these three diameters is obstetrical conjugate, which measures approximately 10.5 cm and is a distance between the sacral promontory and 1 cm below the upper border of the symphysis pubis. This measurement is clinically significant as the fetal head must pass through this diameter during the engagement phase. The transverse diameter measures about 13.5cm and is the widest distance between the innominate line on both sides. 

The shortest distance in the mid pelvis is the interspinous diameter and usually is only about 10 cm. 

Fetal Skull Diameters

There are six distinguished longitudinal fetal skull diameters:

  • Suboccipito-bregmatic: from the center of anterior fontanelle (bregma) to the occipital protuberance, measuring 9.5 cm. This is the presenting diameter in vertex presentation. 
  • Suboccipito-frontal: from the anterior part of bregma to the occipital protuberance, measuring 10 cm 
  • Occipito-frontal: from the root of the nose to the most prominent part of the occiput, measuring 11.5cm
  • Submento-bregmatic: from the center of the bregma to the angle of the mandible, measuring 9.5 cm. This is the presenting diameter in face presentation where the neck is hyperextended. 
  • Submento-vertical: from the midpoint between fontanelles and the angle of the mandible, measuring 11.5cm 
  • Occipito-mental: from the midpoint between fontanelles and the tip of the chin, measuring 13.5 cm. It is the presenting diameter in brow presentation. 

Cardinal Movements of Normal Labor

  • Neck flexion
  • Internal rotation
  • Extension (delivers head)
  • External rotation (Restitution)
  • Expulsion (delivery of anterior and posterior shoulders)

Some of the key movements are not possible in the face or brow presentations.  

Based on the information provided above, it is obvious that labor will be arrested in brow presentation unless it spontaneously changes to face or vertex, as the occipito-mental diameter of the fetal head is significantly wider than the smallest diameter of the female pelvis. Face presentation can, however, be delivered vaginally, and further mechanisms of face delivery will be explained in later sections.

  • Indications

As mentioned previously, spontaneous vaginal delivery can be successful in face presentation. However, the main indication for vaginal delivery in such circumstances would be a maternal choice. It is crucial to have a thorough conversation with a mother, explaining the risks and benefits of vaginal delivery with face presentation and a cesarean section. Informed consent and creating a rapport with the mother is an essential aspect of safe and successful labor.

  • Contraindications

Vaginal delivery of face presentation is contraindicated if the mentum is lying posteriorly or is in a transverse position. In such a scenario, the fetal brow is pressing against the maternal symphysis pubis, and the short fetal neck, which is already maximally extended, cannot span the surface of the maternal sacrum. In this position, the diameter of the head is larger than the maternal pelvis, and it cannot descend through the birth canal. Therefore the cesarean section is recommended as the safest mode of delivery for mentum posterior face presentations. 

Attempts to manually convert face presentation to vertex, manual or forceps rotation of the persistent posterior chin to anterior are contraindicated as they can be dangerous.

Persistent brow presentation itself is a contraindication for vaginal delivery unless the fetus is significantly small or the maternal pelvis is large.

Continuous electronic fetal heart rate monitoring is recommended for face and brow presentations, as heart rate abnormalities are common in these scenarios. One study found that only 14% of the cases with face presentation had no abnormal traces on the cardiotocograph. [8] It is advised to use external transducer devices to prevent damage to the eyes. When internal monitoring is inevitable, it is suggested to place monitoring devices on bony parts carefully. 

People who are usually involved in the delivery of face/ brow presentation are:

  • Experienced midwife, preferably looking after laboring woman 1:1
  • Senior obstetrician 
  • Neonatal team - in case of need for resuscitation 
  • Anesthetic team - to provide necessary pain control (e.g., epidural)
  • Theatre team  - in case of failure to progress and an emergency cesarean section will be required.
  • Preparation

No specific preparation is required for face or brow presentation. However, it is essential to discuss the labor options with the mother and birthing partner and inform members of the neonatal, anesthetic, and theatre co-ordinating teams.

  • Technique or Treatment

Mechanism of Labor in Face Presentation

During contractions, the pressure exerted by the fundus of the uterus on the fetus and pressure of amniotic fluid initiate descent. During this descent, the fetal neck extends instead of flexing. The internal rotation determines the outcome of delivery, if the fetal chin rotates posteriorly, vaginal delivery would not be possible, and cesarean section is permitted. The approach towards mentum-posterior delivery should be individualized, as the cases are rare. Expectant management is acceptable in multiparous women with small fetuses, as a spontaneous mentum-anterior rotation can occur. However, there should be a low threshold for cesarean section in primigravida women or women with large fetuses.

When the fetal chin is rotated towards maternal symphysis pubis as described as mentum-anterior; in these cases further descend through the vaginal canal continues with approximately 73% cases deliver spontaneously. [9] Fetal mentum presses on the maternal symphysis pubis, and the head is delivered by flexion. The occiput is pointing towards the maternal back, and external rotation happens. Shoulders are delivered in the same manner as in vertex delivery.

Mechanism of Labor in Brow Presentation

As this presentation is considered unstable, it is usually converted into a face or an occiput presentation. Due to the cephalic diameter being wider than the maternal pelvis, the fetal head cannot engage; thus, brow delivery cannot take place. Unless the fetus is small or the pelvis is very wide, the prognosis for vaginal delivery is poor. With persistent brow presentation, a cesarean section is required for safe delivery.

  • Complications

As the cesarean section is becoming a more accessible mode of delivery in malpresentations, the incidence of maternal and fetal morbidity and mortality during face presentation has dropped significantly. [10]

However, there are still some complications associated with the nature of labor in face presentation. Due to the fetal head position, it is more challenging for the head to engage in the birth canal and descend, resulting in prolonged labor.

Prolonged labor itself can provoke foetal distress and arrhythmias. If the labor arrests or signs of fetal distress appear on CTG, the recommended next step in management is an emergency cesarean section, which in itself carries a myriad of operative and post-operative complications.

Finally, due to the nature of the fetal position and prolonged duration of labor in face presentation, neonates develop significant edema of the skull and face. Swelling of the fetal airway may also be present, resulting in respiratory distress after birth and possible intubation.

  • Clinical Significance

During vertex presentation, the fetal head flexes, bringing the chin to the chest, forming the smallest possible fetal head diameter, measuring approximately 9.5cm. With face and brow presentation, the neck hyperextends, resulting in greater cephalic diameters. As a result, the fetal head will engage later, and labor will progress more slowly. Failure to progress in labor is also more common in both presentations compared to vertex presentation.

Furthermore, when the fetal chin is in a posterior position, this prevents further flexion of the fetal neck, as browns are pressing on the symphysis pubis. As a result, descend through the birth canal is impossible. Such presentation is considered undeliverable vaginally and requires an emergency cesarean section.

Manual attempts to change face presentation to vertex, manual or forceps rotation to mentum anterior are considered dangerous and are discouraged.

  • Enhancing Healthcare Team Outcomes

A multidisciplinary team of healthcare experts supports the woman and her child during labor and the perinatal period. For a face or brow presentation to be appropriately diagnosed, an experienced midwife and obstetrician must be involved in the vaginal examination and labor monitoring. As fetal anomalies, such as anencephaly or goiter, can contribute to face presentation, sonographers experienced in antenatal scanning should also be involved in the care. It is advised to inform the anesthetic and neonatal teams in advance of the possible need for emergency cesarean section and resuscitation of the neonate. [11] [12]

  • Review Questions
  • Access free multiple choice questions on this topic.
  • Comment on this article.

Disclosure: Julija Makajeva declares no relevant financial relationships with ineligible companies.

Disclosure: Mohsina Ashraf declares no relevant financial relationships with ineligible companies.

This book is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ), which permits others to distribute the work, provided that the article is not altered or used commercially. You are not required to obtain permission to distribute this article, provided that you credit the author and journal.

  • Cite this Page Makajeva J, Ashraf M. Delivery, Face and Brow Presentation. [Updated 2023 Jan 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-.

In this Page

Bulk download.

  • Bulk download StatPearls data from FTP

Related information

  • PubMed Links to PubMed

Similar articles in PubMed

  • Sonographic diagnosis of fetal head deflexion and the risk of cesarean delivery. [Am J Obstet Gynecol MFM. 2020] Sonographic diagnosis of fetal head deflexion and the risk of cesarean delivery. Bellussi F, Livi A, Cataneo I, Salsi G, Lenzi J, Pilu G. Am J Obstet Gynecol MFM. 2020 Nov; 2(4):100217. Epub 2020 Aug 18.
  • Review Sonographic evaluation of the fetal head position and attitude during labor. [Am J Obstet Gynecol. 2022] Review Sonographic evaluation of the fetal head position and attitude during labor. Ghi T, Dall'Asta A. Am J Obstet Gynecol. 2022 Jul 6; . Epub 2022 Jul 6.
  • Stages of Labor. [StatPearls. 2024] Stages of Labor. Hutchison J, Mahdy H, Hutchison J. StatPearls. 2024 Jan
  • Leopold Maneuvers. [StatPearls. 2024] Leopold Maneuvers. Superville SS, Siccardi MA. StatPearls. 2024 Jan
  • Review Labor with abnormal presentation and position. [Obstet Gynecol Clin North Am. ...] Review Labor with abnormal presentation and position. Stitely ML, Gherman RB. Obstet Gynecol Clin North Am. 2005 Jun; 32(2):165-79.

Recent Activity

  • Delivery, Face and Brow Presentation - StatPearls Delivery, Face and Brow Presentation - StatPearls

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

Connect with NLM

National Library of Medicine 8600 Rockville Pike Bethesda, MD 20894

Web Policies FOIA HHS Vulnerability Disclosure

Help Accessibility Careers

statistics

7.10 Brow presentation

Brow presentation constitutes an absolute foeto-pelvic disproportion, and vaginal delivery is impossible (except with preterm birth or extremely low birth weight).

This is an obstetric emergency, because labour is obstructed and there is a risk of uterine rupture and foetal distress.

7.10.1 Diagnosis

  • Head is high; as with a face presentation, there is a cleft between the head and back, but it is less marked.
  • the chin (it is not a face presentation),
  • the posterior fontanelle (it is not a vertex presentation).

Figures 7.9 - Brow presentation

Figure 7-9

Any mobile presenting part can subsequently flex. The diagnosis of brow presentation is, therefore, not made until after the membranes have ruptured and the head has begun to engage in a fixed presentation. Some brow presentations will spontaneously convert to a vertex or, more rarely, a face presentation.

During delivery, the presenting part is slow to descend: the brow is becoming impacted.

7.10.2 Management

Foetus alive.

  • Perform a caesarean section. When performing the caesarean section, an assistant must be ready to free the head by pushing it upward with a hand in the vagina.
  • Convert the brow presentation to a face presentation: between contractions, insert the fingers through the cervix and move the head, encouraging extension (Figures 7.10).
  • Attempt internal podalic version ( Section 7.9 ).

Both these manoeuvres pose a significant risk of uterine rupture. Vacuum extraction, forceps and symphysiotomy are contra-indicated.

the presenting diameter in brow presentation

Foetus dead

Perform an embryotomy if the cervix is sufficiently dilated (Chapter 9, Section 9.7 ) otherwise, a caesarean section.

Planning for a baby?

  • Preconception Health
  • Preparing for Pregnancy
  • Assisted Pregnancy
  • Second Pregnancy

Already Pregnant?

  • Pregnancy Week by Week
  • Health & Safety
  • Live life better
  • Preparing for the baby
  • Pregnancy Diet & Fitness

Have a Baby?

  • Baby Milestones
  • Baby Basics
  • Mother Care
  • Activity & Fun

Have a Toddler?

  • Toddler Mile Stones
  • Toddler Basics
  • Food & Feeding
  • Child Safety & Health
  • Games & Playtime
  • Special Child

Positive Parenting

  • Health & Hyginie
  • Learning and Development
  • Family Basics

Child Safety

  • Special child Care
  • Planning for Future
  • Play, Games, activity & Fun

Life Skills

Premature baby, baby products, health & safety, what is brow presentation what are its complications.

Written by Editorial Team

the presenting diameter in brow presentation

Editorial Team

With a rich experience in pregnancy and parenting, our team of experts create insightful, well-curated, and easy-to-read content for our to-be-parents and parents at all stages of parenting..

the presenting diameter in brow presentation

What Is Brow Presentation?

What leads to brow presentation, diagnosis of brow presentation, how to avoid c-section if baby is in brow presentation, what complications can arise due to brow presentation.

pregnancy pillow

  • Polyhydramnios : Excess amniotic fluid can make it difficult for the baby’s head to take a flexed position
  • Size and shape of the pelvis: Abnormally shaped and sized pelvis can make it difficult for the baby to pick up a vertex presentation. Android pelvis, which has a triangular or heart-shaped inlet with a narrower front part, is usually behind most of the brow presentations. Similarly, contracted pelvis, a pelvis that is abnormally small, can cause brow presentation
  • Fetal abnormality: Fetal abnormalities such as hydrocephalus, anencephaly and neck masses accounts for the majority of brow presentations
  • Premature birth/low birth weight baby: If the baby is born prematurely or if the baby is having low birth weight , the chances of brow presentation increases
  • Big baby : If the baby is larger than normal size, the baby tends to extend its head instead of curling inward
  • Multiple pregnancies: Multiple pregnancies also increase the risk of brow presentation
  • Multiple nuchal cords: If the umbilical cord wraps around the baby’s neck, obviously, it cannot tuck its chin into the chest. In such cases, the baby tends to be brow or face presentations
  • Laxity of the uterus: If the uterine wall loses its firmness, the baby may not able to hold its chin tucked to the chest firmly and the baby tends to be in brow presentation
  • Cephalopelvic disproportion (CPD): If the mother’s pelvis and the baby’s head are not proportionate to each other, brow presentation can happen

brow presentation deliver

  • Manual rotation: Doctor inserts his hand through the cervix and tries to flex the baby’s head
  • The baby’s head should be engaged in the pelvis and should be in a front anterior position
  • The pelvis should have sufficient room to permit the ventouse cup to be inserted posteriorly and to reach the occiput
  • Ability and experience of the obstetrician
  • How favorable is the position of the baby’s head inside the pelvis
  • Available space inside the pelvis
  • Increased chances of spinal cord injury are associated with brow presentation
  • Fetal distress
  • Abnormal shape of the baby’s head after delivery
  • Prolonged labor
  • Increased chances of using forceps which in turn increases the chances of facial trauma
  • Obstructed labor

Advantages Of Saffron During Pregnancy

Saffron is the dried stigma of Crocus Sativus flower, i.e. the thread-like part at the centre which contains pollen.

...

Editorial Team,

With a rich experience in pregnancy and parenting, our team of experts create insightful, well-curated, and easy-to-read content for our to-be-parents and parents at all stages of parenting. Read more.

the presenting diameter in brow presentation

Responses (0)

Want curated content sharply tailored for your exact stage of parenting, read this next.

Related articles

the presenting diameter in brow presentation

Breastfeeding Classes During Pregnancy – Top Benefits and Importance

the presenting diameter in brow presentation

Strawberry During Pregnancy – Why Should This Fruit Be on Your Pregnancy Platter?

the presenting diameter in brow presentation

Infused Waters During Pregnancy – Benefits and Side Effects

the presenting diameter in brow presentation

Samosa During Pregnancy – Is It Safe to Eat?

the presenting diameter in brow presentation

Vaginal Itching During Pregnancy – Symptoms, Causes & Treatment

the presenting diameter in brow presentation

Top 500 Unique Baby Boy Names Starting With S

Sponsored content

Discover great local businesses around you for your kids..

Get regular updates, great recommendations and other right stuff at the right time.

the presenting diameter in brow presentation

Premium Access

Join our community of 50K+ Moms and get access to exclusive features & resources in our app.

Pay Rs 25/- and read this article (One time access)

cookie

Our site uses cookies to make your experience on this site even better. We hope you think that is sweet.

search-icon

Create account

Focus your wanderlust. create your account to get curated stories and recommendations., already have an account sign in.

close-icon

Don't have an account? Sign up forgot password?

Get curated personalized content., articles and resources served personalized as per the stage of your parenting., already have an account login, choose one..

prev-arrow

Enter dates

dropdown-arrow

Wolters Kluwer

Learn how UpToDate can help you.

Select the option that best describes you

  • Medical Professional
  • Resident, Fellow, or Student
  • Hospital or Institution
  • Group Practice
  • Patient or Caregiver
  • Find in topic

RELATED TOPICS

INTRODUCTION

Diagnosis and management of face and brow presentations will be reviewed here. Other cephalic malpresentations are discussed separately. (See "Occiput posterior position" and "Occiput transverse position" .)

Prevalence  —  Face and brow presentation are uncommon. Their prevalences compared with other types of malpresentations are shown below [ 1-9 ]:

● Occiput posterior – 1/19 deliveries

● Breech – 1/33 deliveries

Clinical Gate

  • Register-org
  • Subscriptions

Recent Posts

  • The Influence Of Social Media On Teen ADHD And Parental Insights
  • Healthy in Alaska: 6 Tips to Improve your Well-Being
  • A Buyer’s Guide to RIFE Machines: What to Look for Before You Buy
  • DIY HOME RENOVATIONS: WHAT YOU NEED TO KNOW
  • Legal Recourses After Being Harmed by Someone Else
  • Entries feed
  • Comments feed
  • WordPress.org
  • Allergy and Immunology
  • Anesthesiology
  • Basic Science
  • Cardiothoracic Surgery
  • Cardiovascular
  • Complementary Medicine
  • Critical Care Medicine
  • Dermatology
  • Emergency Medicine
  • Endocrinology, Diabetes and Metabolism
  • Gastroenterology and Hepatology
  • Hematology, Oncology and Palliative Medicine
  • Internal Medicine
  • Medical Education
  • Neonatal – Perinatal Medicine
  • Neurosurgery
  • Nursing & Midwifery & Medical Assistant
  • Obstetrics & Gynecology
  • Opthalmology
  • Orthopaedics
  • Otolaryngology
  • Physical Medicine and Rehabilitation
  • Plastic Reconstructive Surgery
  • Pulmolory and Respiratory
  • Rheumatology

Search Engine

Malpresentations and malpositions.

Published on 09/03/2015 by admin

Filed under Obstetrics & Gynecology

Last modified 09/03/2015

This article have been viewed 9223 times

' src=

Introduction

Malpresentation.

Malposition

During pregnancy, abdominal palpation should aim to define the lie, presentation and position of the fetus. The lie refers to the long axis of the fetus in relation to the long axis of the uterus. Usually, the fetus is longitudinal, but occasionally it may be transverse or oblique. The presentation is that part of the fetus which is at the pelvic brim, in other words the part of the fetus presenting to the pelvic inlet. Normal presentation is the vertex of the fetal head and the word ‘malpresentation’ describes any non-vertex presentation. This may be of the face, brow, breech, or some other part of the body if the lie is oblique or transverse.

The position of the fetus refers to the way in which the presenting part is positioned in relation to the maternal pelvis. Strictly speaking this refers to any presenting part, but here it will be considered in relation to those fetuses presenting head first (cephalic). As we have seen, the head is usually occipitotransverse at the pelvic brim and rotates to occipitoanterior at the pelvic floor. ‘Malposition’ is when the head, coming vertex first, does not rotate to occipitoanterior, presenting instead as persistent occipitotransverse or occipitoposterior.

As described above, ‘malpresentation’ is a term used to describe any non-vertex presentation. Over 95% of fetuses are in cephalic presentation at term. Malpresentations include face presentation, brow presentation and breech presentation. When the fetus has a cephalic presentation, the presenting diameter is dependent on the degree of flexion or extension of the fetal head – deflexed and brow presentations offer a wide diameter to the pelvic inlet ( Table 45.1 and Fig. 45.1 ).

Presenting diameters of the fetal head

the presenting diameter in brow presentation

Fig. 45.1 The presenting diameter is dependent on the degree of flexion or extension of the fetal head.

As the fetal skull is made up of individual bony plates (the occipital, sphenoid, temporal and ethmoid bones), which are joined by cartilaginous sutures (the frontal, sagittal, lambdoid and coronal sutures), it has the potential to be ‘moulded’ during labour. This allows the head to fit the birth canal more closely (Fig. 45.2) . Moulding should be distinguished from caput succedaneum, which refers to oedema of the presenting part of the scalp. Both moulding and caput can occur in any cephalic presentation, but are more likely to occur in malpresentation. The presence or absence of moulding and caput should be documented during each vaginal examination in labour; excessive moulding and caput are suggestive of an obstructed labour due to cephalopelvic disproportion.

the presenting diameter in brow presentation

Fig. 45.2 ‘Moulding’ refers to the change in shape of the fetal skull during labour as it ‘moulds’ to the birth canal.

Caput refers to oedema of the presenting part of the scalp.

Face presentation

This occurs in about 1:500 births and occurs when the fetal head extends right back (hyperextended so that the occiput touches the fetal back) (Fig. 45.3 A) . It is associated with prematurity, tumours of the fetal neck, loops of cord around the fetal neck, fetal macrosomia and anencephaly. Face presentation is usually only recognized after the onset of labour and, if the face is swollen (Fig. 45.3 B) , it is easy to confuse this presentation with that of a breech. The position of the face is described with reference to the chin, using the prefix ‘mento’. The presenting diameter is submentobregmatic (9.5 cm) (Fig. 45.1) .

the presenting diameter in brow presentation

Fig. 45.3 Face presentation.

(A) The head enters the pelvic brim in the transverse position. (B) Most rotate to the mentoanterior position and deliver without problems. (C) Those that rotate to mentoposterior will obstruct. (D) Face presentation is often associated with oedema and bruising. This baby recovered without problems.

The face usually enters the pelvis with the chin in the transverse position (mentotransverse) and 90% rotate to mentoanterior so that the head is born with flexion (Fig. 45.3 C) . If mentoposterior, the extending head presents an increasingly wider diameter to the pelvis, leading to worsening relative cephalopelvic disproportion and impacted obstruction (Fig. 45.3 D) . A caesarean section is usually required.

Brow presentation

This occurs in only approximately 1:700 and 1:1500 births and is the least favourable for delivery (Fig. 45.4) . The presenting diameter is mentovertical, measuring 14 cm. The supraorbital ridges and the bridge of the nose will be palpable on vaginal examination. The head may flex to become a vertex presentation or extend to a face presentation in early labour. If the brow presentation persists, a caesarean section will be required.

the presenting diameter in brow presentation

Fig. 45.4 Brow presentation.

Breech presentation

Breech presentation describes a fetus presenting bottom first. The incidence is around 40% at 20 weeks, 25% at 32 weeks and only 3–4% at term. The chance of a breech presentation turning spontaneously after 38 weeks is < 4%. Breech presentation is associated with multiple pregnancy, bicornuate uterus, fibroids, placenta praevia, polyhydramnios and oligohydramnios. It may also rarely be associated with fetal anomaly, particularly neural tube defects, neuromuscular disorders and autosomal trisomies. At term, 65% of breech presentations are frank (extended) with the remainder being flexed or footling (Fig. 45.5) . Footling breech carries a 5–20% risk of cord prolapse ( p. 367 ).

the presenting diameter in brow presentation

Fig. 45.5 Breech presentation.

Those presenting by the breech may be (A) extended (or frank); (B) flexed; or (C) footling.

Mode of delivery

Share this:.

  • Click to share on Twitter (Opens in new window)
  • Click to share on Facebook (Opens in new window)

Related posts:

the presenting diameter in brow presentation

Clinical Obstetrics and Gynaecology

the presenting diameter in brow presentation

the presenting diameter in brow presentation

Uptodate Reference Title

Face and brow presentations in labor.

INTRODUCTION  —  The vast majority of fetuses at term are in cephalic presentation. Approximately 5 percent of these fetuses are in a cephalic malpresentation, such as occiput posterior or transverse, face ( figure 1A-B ), or brow ( figure 2 ) [ 1 ].

Diagnosis and management of face and brow presentations will be reviewed here. Other cephalic malpresentations are discussed separately. (See "Occiput posterior position" and "Occiput transverse position" .)

Prevalence  —  Face and brow presentation are uncommon. Their prevalences compared with other types of malpresentations are shown below [ 1-9 ]:

● Occiput posterior – 1/19 deliveries

● Breech – 1/33 deliveries

● Face – 1/600 to 1/800 deliveries

● Brow – 1/500 to 1/4000 deliveries

● Transverse lie – 1/833 deliveries

● Compound – 1/1500 deliveries

The prevalence of face presentation at Parkland Memorial Hospital in Texas (United States) has decreased to 1/2000 deliveries in recent years [ 10 ], possibly because of fewer deliveries of fetuses with anomalies such as anencephaly [ 11,12 ]; however, others have not observed a decline [ 9,12,13 ].

Clinical significance  —  During labor in the occiput anterior presentation, the neck normally flexes to bring the chin to the chest, resulting in the relatively small suboccipito-bregmatic diameter (average length 9.5 cm) as the widest cephalic diameter that needs to negotiate the pelvis. This diameter is generally able to traverse the obstetric conjugate (average length 10.5 cm) ( figure 3 ), which is the shortest anteroposterior pelvic diameter. By comparison, the neck is extended in brow and face presentations, which present larger fetal cephalic diameters that need to negotiate the pelvis ( figure 4 ). Thus, protraction or arrest of descent is more likely, which increases the chances of maternal and neonatal morbidity from vaginal birth and the frequency for cesarean birth. Brow and mentum posterior face presentations are most likely to exhibit cephalopelvic dystocia unless the fetus is very small or the maternal pelvis is very large or both. (See 'Neonatal outcome' below and 'Neonatal outcome' below.)

Fetal heart rate abnormalities are more common than with occiput anterior position [ 2,14 ]. They may be due to more head compression or a higher frequency of cord compression.

Risk factors  —  Maternal or fetal anatomic factors that prevent flexion or favor extension of the fetal neck increase the risk for face/brow presentation. These factors include anencephaly, severe hydrocephalus with cephalomegaly, anterior neck mass, multiple nuchal cords, cephalopelvic disproportion, preterm birth/low birth weight, macrosomia, contracted maternal pelvis, platypelloid pelvis ( figure 5 ), multiparity, polyhydramnios, previous cesarean birth, and Black race [ 2,5,8,9,11-13 ].

In multiparous patients, poor abdominal muscle tone may permit the uterine fundus and fetal trunk to swing anteriorly, which may extend the cervical spine, leading to a face or brow presentation [ 13 ]. Alternatively, late engagement of the vertex in multiparous patients, often after the onset of labor, may be the predisposing factor [ 12 ].

A contracted maternal pelvis predisposes to malpresentation [ 12 ]. The increased risk of face/brow presentation in Black patients may be due to differences in pelvic dimensions between White and Black females and a higher rate of preterm birth in Black individuals [ 13,15-17 ]. The differences in pelvic dimensions may be related to environmental differences (eg, locomotion, load carrying, health, nutrition) [ 18 ].

Although preterm birth has been linked to face/brow presentation, possibly because a very small fetus can descend with the neck partially extended, the association between preterm birth and face presentation is weak [ 9,13 ].

Pregnancies with polyhydramnios may be at risk secondary to impaired swallowing due to a fetal anomaly (particularly anencephaly) [ 12 ] or to obstruction of the fetal trachea and esophagus from a hyperextended fetal neck [ 5 ].

FACE PRESENTATION

Definition  —  Face presentation refers to a fetal presentation in which the fetal face from forehead to chin is the leading fetal body part descending into the birth canal ( figure 1B ). The fetal neck is highly extended (sharply deflexed), such that the occiput may touch the back.

Diagnosis  —  The intrapartum diagnosis of face presentation is made by vaginal examination in the late first or the second stage of labor [ 5 ]. Palpation of the orbital ridge and orbits, saddle of the nose, mouth, and chin is diagnostic of face presentation. The fontanelles and sutures are not generally palpable [ 19 ]. At diagnosis, nearly 60 percent of face presentations are mentum anterior, 26 percent are mentum posterior, and 15 percent are mentum transverse, and may be designated as left or right ( figure 1A ) [ 11 ].

Intrapartum transabdominal, translabial, and/or transvaginal sonography of a face presentation will show a hyperextended fetal neck, with the orbits and nasal bridge at the center of the presenting part in the mid-sagittal plane [ 20 ]. Although imaging studies can be performed to confirm the diagnosis if it is uncertain, imaging is not mandatory, and results do not have prognostic value for predicting the outcome of labor [ 21 ].

Differential diagnosis  —  Face presentation may be misdiagnosed as a frank breech presentation on digital examination since the latter is more commonly encountered (and therefore expected). Both presentations are characterized by soft tissues with an orifice; however, careful palpation will identify the bony facial structures and lead to the correct diagnosis. With ultrasound readily available in most delivery units, confirmation of the type of malpresentation (breech or face) is easily obtained if needed.

Labor and delivery management

Fetal heart rate monitoring  —  The fetal heart rate is monitored continuously, ideally with an external device. An internal device may cause facial or ophthalmic injuries if improperly placed [ 22-24 ]. If internal monitoring is required, the electrode should be carefully applied over a bony structure such as the forehead, mandible, or zygomatic bones to minimize the risk of trauma [ 25 ].

Abnormalities of the fetal heart rate occur more frequently with face presentations [ 4,25,26 ]. In one series, severe variable and late decelerations developed in 29 and 24 percent of labors, respectively [ 25 ]. Only 14 percent of pregnancies had normal tracings. Moreover, 13 percent of the newborns had a low five-minute Apgar score.

Interpretation and management of abnormal fetal heart rate tracings are not affected by fetal presentation and are reviewed separately. We perform amnioinfusion for patients with variable decelerations (category 2 tracing), regardless of presentation, as long as vaginal birth is anticipated. (See "Intrapartum category I, II, and III fetal heart rate tracings: Management" .)

Mentum anterior  —  In mentum anterior face presentation, the fetal chin needs to pass under the symphysis pubis. For this to occur, the extended fetal neck may need to extend even more. After the chin clears the symphysis, further descent and fetal expulsion can occur [ 5 ]. Over 75 percent of mentum anterior fetuses are born vaginally [ 2,3,13,26,27 ].

The parturient may begin pushing at full dilation. Labor progress should be closely monitored as arrest of descent may occur, although not inevitably as in persistent mentum posterior position.

Oxytocin augmentation and cesarean birth are performed for standard obstetric indications [ 26 ]. (See "Labor: Overview of normal and abnormal progression" .)

Attempts at version or vacuum- or midforceps-assisted delivery should be avoided as they are associated with unnecessary maternal trauma and neonatal injury [ 28 ].

An outlet forceps-assisted delivery when the face is distending the perineum is not contraindicated if delivery must be facilitated but should only be performed by experienced clinicians familiar with the particular considerations involved. For example, in contrast to the occiput anterior position, engagement does not occur until the face is at +2 station [ 5 ]; the chin rather than the occiput is the focal point for orientation; and if Kielland forceps are applied, the left blade is applied to the right side of the head and the right blade to the left side [ 29,30 ]. The technique of forceps delivery is beyond the scope of this review.

Mentum posterior  —  In the mentum posterior face presentation, the fetal neck is already maximally extended and cannot extend further to allow the occiput to pass under the symphysis. Therefore, the mentum posterior face presentation will not deliver vaginally unless spontaneous rotation to mentum anterior occurs ( figure 6 ), often late in the second stage of labor [ 14 ], or the fetus is very small, or the pelvis is very large. If the fetal status is reassuring and there is normal labor progress, mentum posterior presentation can be managed expectantly to see if spontaneous rotation will occur [ 14 ].

Patients with abnormal labor progression are delivered by cesarean. We individualize management when labor is progressing. For example, in multiparous patients with an adequate pelvis and fetus estimated to weigh less than their prior newborns, we would follow labor progress closely and maintain a low threshold for abandoning attempts at vaginal birth if labor does not progress normally in the first or second stage. However, if the fetus is estimated to be larger than their prior newborns, or in nulliparous patients, we would recommend cesarean birth early in the labor course. There is consensus that assisted vaginal delivery is contraindicated for mentum posterior presentations [ 14,31,32 ].

In the past, manual version of the mentum posterior face to an occiput anterior or mentum anterior position was attempted using internal and external manipulation [ 33,34 ]. Although some clinicians have been successful with no serious neonatal or maternal complications, others have reported maternal deaths from uterine rupture, cord prolapse resulting in neonatal asphyxia, and cervical spine trauma resulting in severe neonatal neurologic sequelae [ 28 ]. Given the safety and ready availability of cesarean birth, we believe internal version should be reserved for occasions when cesarean birth is unable to be accomplished due to lack of surgical facilities and inability to arrange maternal transport, or absolute maternal refusal to allow a cesarean birth [ 34 ].

Mentum transverse  —  There are minimal published data on management of the mentum transverse position. Our management is the same as for mentum posterior.

Neonatal outcome  —  Prior to 1955, increased rates of intrapartum fetal death and perinatal mortality (approximately 10 percent) were reported for face presentation [ 5 ]. Perinatal mortality decreased to 2 to 3 percent by 1980, likely due to the increased use of cesarean birth, as well as other advances in obstetric and neonatal care [ 5 ]. Recent perinatal mortality data are not available.

Neonates who were in face presentation often have significant facial edema, facial bruising/ecchymosis, and skull molding [ 35 ]. This usually resolves within the first 24 to 48 hours of life. Personnel and equipment for performing endotracheal intubation should be readily available at birth [ 25 ]. Difficulty in ventilation during resuscitation has been reported and attributed to tracheal and laryngeal trauma and edema.

Facial trauma and spinal cord injury have also been described in case reports and are often associated with version, extraction, and midforceps rotations [ 2,23-25,36 ]. Appropriate management of face presentation, as described above, typically does not result in increased serious maternal or neonatal morbidity [ 2 ].

BROW PRESENTATION

Definition  —  Brow presentation refers to a presentation in which the fetal surface presenting in the birth canal extends from the anterior fontanelle to the brow (orbital ridge), but does not include the mouth and chin ( figure 2 ). The fetal neck is extended, but not to the degree of a face presentation.

Diagnosis  —  The diagnosis of brow presentation is made by vaginal examination in the second stage of labor [ 5 ]. Palpation of the forehead, orbital ridge, orbits, and saddle of the nose, but not the mouth and chin, is diagnostic of brow presentation. The anterior fontanelle is palpable, but the sagittal suture generally is not [ 19 ]. The brow may be anterior or posterior and described by the position or the anterior fontanelle as frontal anterior, transverse, or posterior [ 14 ].

There is increasing evidence that ultrasound is more accurate than vaginal examination for determining fetal position and can be used to determine or confirm abnormal presentation [ 37,38 ]. On transabdominal examination, if the occiput is anterior, the main finding is a reduction in occiput-spinal angle, usually around 90 degrees rather than over 120 degrees; if the occiput is posterior, the chin is separate from chest, and the cervical spine is curved (convex) anteriorly [ 19 ]. If a transperineal examination is performed, the fetal orbits are seen at the same level as the pubic symphysis.

Labor and delivery management  —  The fetal heart rate is monitored continuously during labor, ideally with an external device, since fetal heart rate abnormalities are more common than with occiput anterior position. An internal device may cause facial or ophthalmic injuries if improperly placed [ 22-24 ]. If internal monitoring is required, the electrode should be cautiously applied over a bony structure, such as the forehead, to minimize the risk of trauma [ 25 ].

Patients with a clinically adequate or proven pelvis can undergo a trial of labor since many brow presentations are transitional. In one review, when brow presentation was diagnosed early in labor, 67 to 75 percent of fetuses spontaneously converted to a more favorable presentation and delivered vaginally. When diagnosed late in labor, 50 percent spontaneously converted and delivered vaginally: in 30 percent, the neck extended further resulting in mentum anterior face presentation; in 20 percent, the neck flexed resulting in an occiput posterior presentation [ 2,5,39 ]. Conversion to occiput anterior is rare.

If the brow presentation persists, labor progress is usually protracted or arrests, necessitating cesarean birth. Oxytocin augmentation is not recommended in this setting, given the association between brow presentation and cephalopelvic disproportion [ 5,26,33 ]. Version or vacuum- or forceps-assisted delivery are not recommended, as the risks for maternal and fetal injury are high [ 5,14,31,32 ]. However, in settings where cesarean birth is not readily available, vacuum-assisted flexion of the fetal head may be considered [ 40 ].

In a minority of cases, spontaneous vaginal birth may be possible if the fetus is extremely small or macerated or the maternal pelvis is unusually large.

Neonatal outcome  —  Recognition and appropriate management of brow presentation, as described above, typically do not result in increased serious maternal or neonatal morbidity.

SOCIETY GUIDELINE LINKS  —  Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Labor" .)

SUMMARY AND RECOMMENDATIONS

Issues common to face and brow presentations

● Risk factors – Face and brow presentations are associated with multiparity, cephalopelvic disproportion, preterm birth, polyhydramnios, and fetal anomalies (eg, anencephaly, anterior neck mass). (See 'Risk factors' above.)

● Clinical significance – The deflexed neck in face or brow presentation inhibits head engagement and subsequent fetal descent. (See 'Clinical significance' above.)

● Cautions – The fetal heart rate is monitored continuously during labor, ideally with an external device, because of the increased prevalence of fetal heart rate decelerations. An internal device may cause facial or ophthalmic injuries if improperly placed. If internal monitoring is required, the electrode should be carefully applied over a bony structure to minimize the risk of trauma. (See 'Labor and delivery management' above.)

● Definition – In face presentation, the fetal face from forehead to chin is the leading fetal body part descending into the birth canal ( figure 1B ). The fetal neck is sharply deflexed and the occiput may touch the back. Nearly 60 percent of face presentations are mentum anterior, 26 percent are mentum posterior, and 15 percent are mentum transverse, and may be designated as left or right ( figure 1A ). (See 'Definition' above.)

● Diagnosis – The diagnosis of face presentation is made by vaginal examination. Palpation of the orbital ridge and orbits, saddle of the nose, mouth, and chin is diagnostic of face presentation ( figure 1A ). Ultrasound can be used to confirm or clarify the type of malpresentation if the clinical examination findings are unclear. (See 'Diagnosis' above.)

● Management

• Mentum anterior – Over 75 percent of mentum anterior fetuses deliver vaginally; this rate is similar to that for all fetuses in cephalic presentations. For face presentation with the mentum anterior, we suggest a trial of labor rather than cesarean birth ( Grade 2C ). Oxytocin augmentation may be administered in the setting of a normal fetus with protracted labor, as long as the fetal heart rate pattern remains reassuring. (See 'Labor and delivery management' above.)

• Mentum posterior – The mentum posterior face presentation will not deliver vaginally unless spontaneous rotation occurs, which is infrequent and occurs late in the second stage of labor, or the fetus is very small or the pelvis very large or both. As mentum posterior presentations are rare, we individualize management of such situations. In a multiparous patient with an adequate pelvis and fetus estimated to weigh less than her prior newborns, we follow labor progress closely and maintain a low threshold for abandoning attempts at vaginal birth if labor does not progress normally in the first or second stage. We recommend cesarean birth rather than manual rotation ( Grade 1C ).

If the fetus is estimated to be larger than the patient’s prior newborns or the patient is nulliparous, we perform cesarean birth early in the labor course. (See 'Labor and delivery management' above.)

● Definition – In brow presentation, the fetal surface presenting in the birth canal extends from the anterior fontanelle to the brow (orbital ridge), but does not include the mouth and chin ( figure 2 ). The fetal neck is extended, but not to the degree of a face presentation. (See 'Definition' above.)

● Diagnosis – The diagnosis of brow presentation is made by vaginal examination. Palpation of the forehead, orbital ridge, orbits, and saddle of the nose, but not the mouth and chin, is diagnostic of brow presentation ( figure 2 ). Ultrasound can be used to confirm or clarify the type of malpresentation if the clinical examination findings are unclear. (See 'Diagnosis' above.)

● Management – Patients with a fetus in brow presentation and a clinically adequate or proven pelvis can undergo a trial of labor, with close monitoring and delivery by cesarean for standard indications. The brow presentation is often a transitional state: 50 percent will spontaneously convert to a face or occipital presentation. Fetuses with persistent brow presentation should be delivered by cesarean since vaginal birth is not possible unless the fetus is very small, the pelvis is very large, or both. Operative vaginal delivery is contraindicated for brow presentation. (See 'Labor and delivery management' above.)

  • Gardberg M, Leonova Y, Laakkonen E. Malpresentations--impact on mode of delivery. Acta Obstet Gynecol Scand 2011; 90:540.
  • Duff P. Diagnosis and management of face presentation. Obstet Gynecol 1981; 57:105.
  • Ducarme G, Ceccaldi PF, Chesnoy V, et al. [Face presentation: retrospective study of 32 cases at term]. Gynecol Obstet Fertil 2006; 34:393.
  • Bhal PS, Davies NJ, Chung T. A population study of face and brow presentation. J Obstet Gynaecol 1998; 18:231.
  • Cruikshank DP, Cruikshank JE. Face and brow presentation: a review. Clin Obstet Gynecol 1981; 24:333.
  • Weissberg SM, O'Leary JA. Compound presentation of the fetus. Obstet Gynecol 1973; 41:60.
  • Ingólfsson A. Brow presentations. Acta Obstet Gynecol Scand 1969; 48:486.
  • Tapisiz OL, Aytan H, Altinbas SK, et al. Face presentation at term: a forgotten issue. J Obstet Gynaecol Res 2014; 40:1573.
  • Zayed F, Amarin Z, Obeidat B, et al. Face and brow presentation in northern Jordan, over a decade of experience. Arch Gynecol Obstet 2008; 278:427.
  • Cunningham FG, Leveno KJ, Bloom SL, et al. Williams Obstetrics, 25th ed, McGraw-Hill Education, New York 2018.
  • Cruikshank DP, White CA. Obstetric malpresentations: twenty years' experience. Am J Obstet Gynecol 1973; 116:1097.
  • Bashiri A, Burstein E, Bar-David J, et al. Face and brow presentation: independent risk factors. J Matern Fetal Neonatal Med 2008; 21:357.
  • Shaffer BL, Cheng YW, Vargas JE, et al. Face presentation: predictors and delivery route. Am J Obstet Gynecol 2006; 194:e10.
  • Sharshiner R, Silver RM. Management of fetal malpresentation. Clin Obstet Gynecol 2015; 58:246.
  • Handa VL, Lockhart ME, Fielding JR, et al. Racial differences in pelvic anatomy by magnetic resonance imaging. Obstet Gynecol 2008; 111:914.
  • Işcan MY. Assessment of race from the pelvis. Am J Phys Anthropol 1983; 62:205.
  • Patriquin ML, Steyn M, Loth SR. Metric analysis of sex differences in South African black and white pelves. Forensic Sci Int 2005; 147:119.
  • Kurki HK, Decrausaz SL. Shape variation in the human pelvis and limb skeleton: Implications for obstetric adaptation. Am J Phys Anthropol 2016; 159:630.
  • Bellussi F, Ghi T, Youssef A, et al. The use of intrapartum ultrasound to diagnose malpositions and cephalic malpresentations. Am J Obstet Gynecol 2017; 217:633.
  • Lau WL, Cho LY, Leung WC. Intrapartum translabial ultrasound demonstration of face presentation during first stage of labor. J Obstet Gynaecol Res 2011; 37:1868.
  • Ghi T, Eggebø T, Lees C, et al. ISUOG Practice Guidelines: intrapartum ultrasound. Ultrasound Obstet Gynecol 2018; 52:128.
  • Lauer AK, Rimmer SO. Eyelid laceration in a neonate by fetal monitoring spiral electrode. Am J Ophthalmol 1998; 125:715.
  • Miyashiro MJ, Mintz-Hittner HA. Penetrating ocular injury with a fetal scalp monitoring spiral electrode. Am J Ophthalmol 1999; 128:526.
  • Cheng BT, Laurenti KD, Kurup SP. Neonatal eyelid penetration from insertion of a fetal scalp electrode: a case report. BMC Pregnancy Childbirth 2022; 22:878.
  • Benedetti TJ, Lowensohn RI, Truscott AM. Face presentation at term. Obstet Gynecol 1980; 55:199.
  • Schwartz Z, Dgani R, Lancet M, Kessler I. Face presentation. Aust N Z J Obstet Gynaecol 1986; 26:172.
  • Westgren M, Svenningsen NW. Face presentation in modern obstetrics--a study with special reference to fetal long term morbidity. Z Geburtshilfe Perinatol 1984; 188:87.
  • Vialle R, Piétin-Vialle C, Ilharreborde B, et al. Spinal cord injuries at birth: a multicenter review of nine cases. J Matern Fetal Neonatal Med 2007; 20:435.
  • Dennen PC. Dennen's Forceps Deliveries, 3rd edition, FA Davis, Philadelphia 1989. p.127.
  • Laufe LE. Obstetric Forceps, Harper & Row, Hagerstown 1968. p.117.
  • Yeomans ER, Hoffman BL, Gilstrap LC, Cunningham FG. Operative vaginal delivery. In: Cunningham and Gilstrap's Operative Obstetrics, 3rd ed, McGraw-Hill Education, New York 2017.
  • Shabib G, Black, A. Operative vaginal delivery. In: Oxorn-Foote Human Labor and Birth, 6th ed, Posner G (Ed), McGraw-Hill Medical, New York 2013.
  • Levy DL. Persistent brow presentation: a new approach to management. South Med J 1976; 69:191.
  • Neuman M, Beller U, Lavie O, et al. Intrapartum bimanual tocolytic-assisted reversal of face presentation: preliminary report. Obstet Gynecol 1994; 84:146.
  • Williams Obstetrics, 23rd Ed, Cunningham, FG, Leveno, KJ, Bloom, JC, et al (Eds), McGraw-Hill, 2010.
  • Vialle R, Piétin-Vialle C, Vinchon M, et al. Birth-related spinal cord injuries: a multicentric review of nine cases. Childs Nerv Syst 2008; 24:79.
  • Lau WL, Leung WC, Chin R. Intrapartum translabial ultrasound demonstrating brow presentation during the second stage of labor. Int J Gynaecol Obstet 2009; 107:62.
  • Wiafe YA, Whitehead B, Venables H, Nakua EK. The effectiveness of intrapartum  ultrasonography in assessing cervical dilatation, head station and position: A systematic review and meta-analysis. Ultrasound 2016; 24:222.
  • Jennings PN. Brow presentation with vaginal delivery. Aust N Z J Obstet Gynaecol 1968; 8:219.
  • Luker R. Vaginal delivery of two cases of brow presentation using multiple Kiwi Omnicups. J Obstet Gynaecol 2005; 25:601.

1 : Malpresentations--impact on mode of delivery.

2 : Diagnosis and management of face presentation.

3 : [Face presentation: retrospective study of 32 cases at term].

4 : A population study of face and brow presentation.

5 : Face and brow presentation: a review.

6 : Compound presentation of the fetus.

7 : Brow presentations.

8 : Face presentation at term: a forgotten issue.

9 : Face and brow presentation in northern Jordan, over a decade of experience.

10 : Face and brow presentation in northern Jordan, over a decade of experience.

11 : Obstetric malpresentations: twenty years' experience.

12 : Face and brow presentation: independent risk factors.

13 : Face presentation: predictors and delivery route.

14 : Management of fetal malpresentation.

15 : Racial differences in pelvic anatomy by magnetic resonance imaging.

16 : Assessment of race from the pelvis.

17 : Metric analysis of sex differences in South African black and white pelves.

18 : Shape variation in the human pelvis and limb skeleton: Implications for obstetric adaptation.

19 : The use of intrapartum ultrasound to diagnose malpositions and cephalic malpresentations.

20 : Intrapartum translabial ultrasound demonstration of face presentation during first stage of labor.

21 : ISUOG Practice Guidelines: intrapartum ultrasound.

22 : Eyelid laceration in a neonate by fetal monitoring spiral electrode.

23 : Penetrating ocular injury with a fetal scalp monitoring spiral electrode.

24 : Neonatal eyelid penetration from insertion of a fetal scalp electrode: a case report.

25 : Face presentation at term.

26 : Face presentation.

27 : Face presentation in modern obstetrics--a study with special reference to fetal long term morbidity.

28 : Spinal cord injuries at birth: a multicenter review of nine cases.

29 : Spinal cord injuries at birth: a multicenter review of nine cases.

30 : Spinal cord injuries at birth: a multicenter review of nine cases.

31 : Spinal cord injuries at birth: a multicenter review of nine cases.

32 : Spinal cord injuries at birth: a multicenter review of nine cases.

33 : Persistent brow presentation: a new approach to management.

34 : Intrapartum bimanual tocolytic-assisted reversal of face presentation: preliminary report.

35 : Intrapartum bimanual tocolytic-assisted reversal of face presentation: preliminary report.

36 : Birth-related spinal cord injuries: a multicentric review of nine cases.

37 : Intrapartum translabial ultrasound demonstrating brow presentation during the second stage of labor.

38 : The effectiveness of intrapartum ultrasonography in assessing cervical dilatation, head station and position: A systematic review and meta-analysis.

39 : Brow presentation with vaginal delivery.

40 : Vaginal delivery of two cases of brow presentation using multiple Kiwi Omnicups.

آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟

اضافه کردن مدیلیب به صفحه اصلی

iphoneAddToHomeScreen

the presenting diameter in brow presentation

Face and Brow Presentation

  • Author: Teresa Marino, MD; Chief Editor: Carl V Smith, MD  more...
  • Sections Face and Brow Presentation
  • Mechanism of Labor
  • Labor Management

At the onset of labor, assessment of the fetal presentation with respect to the maternal birth canal is critical to the route of delivery. At term, the vast majority of fetuses present in the vertex presentation, where the fetal head is flexed so that the chin is in contact with the fetal thorax. The fetal spine typically lies along the longitudinal axis of the uterus. Nonvertex presentations (including breech, transverse lie, face, brow, and compound presentations) occur in less than 4% of fetuses at term. Malpresentation of the vertex presentation occurs if there is deflexion or extension of the fetal head leading to brow or face presentation, respectively.

In a face presentation, the fetal head and neck are hyperextended, causing the occiput to come in contact with the upper back of the fetus while lying in a longitudinal axis. The presenting portion of the fetus is the fetal face between the orbital ridges and the chin. The fetal chin (mentum) is the point designated for reference during an internal examination through the cervix. The occiput of a vertex is usually hard and has a smooth contour, while the face and brow tend to be more irregular and soft. Like the occiput, the mentum can present in any position relative to the maternal pelvis. For example, if the mentum presents in the left anterior quadrant of the maternal pelvis, it is designated as left mentum anterior (LMA).

In a brow presentation, the fetal head is midway between full flexion (vertex) and hyperextension (face) along a longitudinal axis. The presenting portion of the fetal head is between the orbital ridge and the anterior fontanel. The face and chin are not included. The frontal bones are the point of designation and can present (as with the occiput during a vertex delivery) in any position relative to the maternal pelvis. When the sagittal suture is transverse to the pelvic axis and the anterior fontanel is on the right maternal side, the fetus would be in the right frontotransverse position (RFT).

Face presentation occurs in 1 of every 600-800 live births, averaging about 0.2% of live births. Causative factors associated with a face presentation are similar to those leading to general malpresentation and those that prevent head flexion or favor extension. Possible etiology includes multiple gestations, grand multiparity, fetal malformations, prematurity, and cephalopelvic disproportion. At least one etiological factor may be identified in up to 90% of cases with face presentation.

Fetal anomalies such as hydrocephalus, anencephaly, and neck masses are common risk factors and may account for as many as 60% of cases of face presentation. For example, anencephaly is found in more than 30% of cases of face presentation. Fetal thyromegaly and neck masses also lead to extension of the fetal head.

A contracted pelvis or cephalopelvic disproportion, from either a small pelvis or a large fetus, occurs in 10-40% of cases. Multiparity or a large abdomen can cause decreased uterine tone, leading to natural extension of the fetal head.

Face presentation is diagnosed late in the first or second stage of labor by examination of a dilated cervix. On digital examination, the distinctive facial features of the nose, mouth, and chin, the malar bones, and particularly the orbital ridges can be palpated. This presentation can be confused with a breech presentation because the mouth may be confused with the anus and the malar bones or orbital ridges may be confused with the ischial tuberosities. The facial presentation has a triangular configuration of the mouth to the orbital ridges compared to the breech presentation of the anus and fetal genitalia. During Leopold maneuvers, diagnosis is very unlikely. Diagnosis can be confirmed by ultrasound evaluation, which reveals a hyperextended fetal neck.

Brow presentation is the least common of all fetal presentations and the incidence varies from 1 in 500 deliveries to 1 in 1400 deliveries. Brow presentation may be encountered early in labor but is usually a transitional state and converts to a vertex presentation after the fetal neck flexes. Occasionally, further extension may occur resulting in a face presentation.

The causes of a persistent brow presentation are generally similar to those causing a face presentation and include cephalopelvic disproportion or pelvic contracture, increasing parity and prematurity. These are implicated in more than 60% of cases of persistent brow presentation. Premature rupture of membranes may precede brow presentation in as many as 27% of cases.

Diagnosis of a brow presentation can occasionally be made with abdominal palpation by Leopold maneuvers. A prominent occipital prominence is encountered along the fetal back, and the fetal chin is also palpable; however, the diagnosis of a brow presentation is usually confirmed by examination of a dilated cervix. The orbital ridge, eyes, nose, forehead, and anterior fontanelle are palpated. The mouth and chin are not palpable, thus excluding face presentation. Fetal ultrasound evaluation again notes a hyperextended neck.

As with face presentation, diagnosis is often made late in labor with half of cases occurring in the second stage of labor. The most common position is the mentum anterior, which occurs about twice as often as either transverse or posterior positions. A higher cesarean delivery rate occurs with a mentum transverse or posterior [ 1 ] position than with a mentum anterior position.

The mechanism of labor consists of the cardinal movements of engagement, descent, flexion, internal rotation, and the accessory movements of extension and external rotation. Intuitively, the cardinal movements of labor for a face presentation are not completely identical to those of a vertex presentation.

While descending into the pelvis, the natural contractile forces combined with the maternal pelvic architecture allow the fetal head to either flex or extend. In the vertex presentation, the vertex is flexed such that the chin rests on the fetal chest, allowing the suboccipitobregmatic diameter of approximately 9.5 cm to be the widest diameter through the maternal pelvis. This is the smallest of the diameters to negotiate the maternal pelvis. Following engagement in the face presentation, descent is made. The widest diameter of the fetal head negotiating the pelvis is the trachelobregmatic or submentobregmatic diameter, which is 10.2 cm (0.7 cm larger than the suboccipitobregmatic diameter). Because of this increased diameter, engagement does not occur until the face is at +2 station.

Fetuses with face presentation may initially begin labor in the brow position. Using x-ray pelvimetry in a series of 7 patients, Borrell and Ferstrom demonstrated that internal rotation occurs between the ischial spines and the ischial tuberosities, making the chin the presenting part, lower than in the vertex presentation. [ 2 , 3 ] Following internal rotation, the mentum is below the maternal symphysis, and delivery occurs by flexion of the fetal neck. As the face descends onto the perineum, the anterior fetal chin passes under the symphysis and flexion of the head occurs, making delivery possible with maternal expulsive forces.

The above mechanisms of labor in the term infant can occur only if the mentum is anterior and at term, only the mentum anterior face presentation is likely to deliver vaginally. If the mentum is posterior or transverse, the fetal neck is too short to span the length of the maternal sacrum and is already at the point of maximal extension. The head cannot deliver as it cannot extend any further through the symphysis and cesarean delivery is the safest route of delivery.

Fortunately, the mentum is anterior in over 60% of cases of face presentation, transverse in 10-12% of cases, and posterior only 20-25% of the time. Fetuses with the mentum transverse position usually rotate to the mentum anterior position, and 25-33% of fetuses with mentum posterior position rotate to a mentum anterior position. When the mentum is posterior, the neck, head and shoulders must enter the pelvis simultaneously, resulting in a diameter too large for the maternal pelvis to accommodate unless in the very preterm or small infant.

Three labor courses are possible when the fetal head engages in a brow presentation. The brow may convert to a vertex presentation, to a face presentation, or remain as a persistent brow presentation. More than 50% of brow presentations will convert to vertex or face presentation and labor courses are managed accordingly when spontaneous conversion occurs.

In the brow presentation, the occipitomental diameter, which is the largest diameter of the fetal head, is the presenting portion. Descent and internal rotation occur only with an adequate pelvis and if the face can fit under the pubic arch. While the head descends, it becomes wedged into the hollow of the sacrum. Downward pressure from uterine contractions and maternal expulsive forces may cause the mentum to extend anteriorly and low to present at the perineum as a mentum anterior face presentation.

If internal rotation does not occur, the occipitomental diameter, which measures 1.5 cm wider than the suboccipitobregmatic diameter and is thus the largest diameter of the fetal head, presents at the pelvic inlet. The head may engage but can descend only with significant molding. This molding and subsequent caput succedaneum over the forehead can become so extensive that identification of the brow by palpation is impossible late in labor. This may result in a missed diagnosis in a patient who presents later in active labor.

If the mentum is anterior and the forces of labor are directed toward the fetal occiput, flexing the head and pivoting the face under the pubic arch, there is conversion to a vertex occiput posterior position. If the occiput lies against the sacrum and the forces of labor are directed against the fetal mentum, the neck may extend further, leading to a face presentation.

The persistent brow presentation with subsequent delivery only occurs in cases of a large pelvis and/or a small infant. Women with gynecoid pelvis or multiparity may be given the option to labor; however, dysfunctional labor and cephalopelvic disproportion are more likely if this presentation persists.

Labor management of face and brow presentation requires close observation of labor progression because cephalopelvic disproportion, dysfunctional labor, and prolonged labor are much more common. As mentioned above, the trachelobregmatic or submentobregmatic diameters are larger than the suboccipitobregmatic diameter. Duration of labor with a face presentation is generally the same as duration of labor with a vertex presentation, although a prolonged labor may occur. As long as maternal or fetal compromise is not evident, labor with a face presentation may continue. [ 4 ] A persistent mentum posterior presentation is an indication for delivery by cesarean section.

Continuous electronic fetal heart rate monitoring is considered mandatory by many authors because of the increased incidence of abnormal fetal heart rate patterns and/or nonreassuring fetal heart rate patterns. [ 5 ] An internal fetal scalp electrode may be used, but very careful application of the electrode must be ensured. The mentum is the recommended site of application. Facial edema is common and can obscure the fetal facial anatomy and improper placement can lead to facial and ophthalmic injuries. Oxytocin can be used to augment labor using the same precautions as in a vertex presentation and the same criteria of assessment of uterine activity, adequacy of the pelvis, and reassuring fetal heart tracing.

Fetuses with face presentation can be delivered vaginally with overall success rates of 60-70%, while more than 20% of fetuses with face presentation require cesarean delivery. Cesarean delivery is performed for the usual obstetrical indications, including arrest of labor and nonreassuring fetal heart rate pattern.

Attempts to manually convert the face to vertex (Thom maneuver) or to rotate a posterior position to a more favorable anterior mentum position are rarely successful and are associated with high fetal morbidity and mortality and maternal morbidity, including cord prolapse, uterine rupture, and fetal cervical spine injury with neurological impairment. Given the availability and safety of cesarean delivery, internal rotation maneuvers are no longer justified unless cesarean section cannot be readily performed.

Internal podalic version and breech extraction are also no longer recommended in the modern management of the face presentation. [ 6 ]

Operative delivery with forceps must be approached with caution. Since engagement occurs when the face is at +2 position, forceps should only be applied to the face that has caused the perineum to bulge. Increased complications to both mother and fetus can occur [ 7 ] and operative delivery must be approached with caution or reserved when cesarean section is not readily available. Forceps may be used if the mentum is anterior. Although the landmarks are different, the application of any forceps is made as if the fetus were presenting directly in the occiput anterior position. The mouth substitutes for the posterior fontanelle, and the mentum substitutes for the occiput. Traction should be downward to maintain extension until the mentum passes under the symphysis, and then gradually elevated to allow the head to deliver by flexion. During delivery, hyperextension of the fetal head should be avoided.

As previously mentioned, the persistent brow presentation has a poor prognosis for vaginal delivery unless the fetus is small, premature, or the maternal pelvis is large. Expectant management is reasonable if labor is progressing well and the fetal well-being is assessed, as there can be spontaneous conversion to face or vertex presentation. The earlier in labor that brow presentation is diagnosed, the higher the likelihood of conversion. Minimal intervention during labor is recommended and some feel the use of oxytocin in the brow presentation is contraindicated.

The use of operative vaginal delivery or manual conversion of a brow to a more favorable presentation is contraindicated as the risks of perinatal morbidity and mortality are unacceptably high. Prolonged, dysfunctional, and arrest of labor are common, necessitating cesarean section delivery.

The incidence of perinatal morbidity and mortality and maternal morbidity has decreased due to the increased incidence of cesarean section delivery for malpresentation, including face and brow presentation.

Neonates delivered in the face presentation exhibit significant facial and skull edema, which usually resolves within 24-48 hours. Trauma during labor may cause tracheal and laryngeal edema immediately after delivery, which can result in neonatal respiratory distress. In addition, fetal anomalies or tumors, such as fetal goiters that may have contributed to fetal malpresentation, may make intubation difficult. Physicians with expertise in neonatal resuscitation should be present at delivery in the event that intubation is required. When a fetal anomaly has been previously diagnosed by ultrasonographic evaluation, the appropriate pediatric specialists should be consulted and informed at time of labor.

Shaffer BL, Cheng YW, Vargas JE, Laros RK Jr, Caughey AB. Face presentation: predictors and delivery route. Am J Obstet Gynecol . 2006 May. 194(5):e10-2. [QxMD MEDLINE Link] .

Borell U, Fernstrom I. The mechanism of labour. Radiol Clin North Am . 1967 Apr. 5(1):73-85. [QxMD MEDLINE Link] .

Borell U, Fernstrom I. The mechanism of labour in face and brow presentation: a radiographic study. Acta Obstet Gynecol Scand . 1960. 39:626-44.

Gardberg M, Leonova Y, Laakkonen E. Malpresentations--impact on mode of delivery. Acta Obstet Gynecol Scand . 2011 May. 90(5):540-2. [QxMD MEDLINE Link] .

Collaris RJ, Oei SG. External cephalic version: a safe procedure? A systematic review of version-related risks. Acta Obstet Gynecol Scand . 2004 Jun. 83(6):511-8. [QxMD MEDLINE Link] .

Verspyck E, Bisson V, Gromez A, Resch B, Diguet A, Marpeau L. Prophylactic attempt at manual rotation in brow presentation at full dilatation. Acta Obstet Gynecol Scand . 2012 Nov. 91(11):1342-5. [QxMD MEDLINE Link] .

Johnson JH, Figueroa R, Garry D. Immediate maternal and neonatal effects of forceps and vacuum-assisted deliveries. Obstet Gynecol . 2004 Mar. 103(3):513-8. [QxMD MEDLINE Link] .

Benedetti TJ, Lowensohn RI, Truscott AM. Face presentation at term. Obstet Gynecol . 1980 Feb. 55(2):199-202. [QxMD MEDLINE Link] .

BROWNE AD, CARNEY D. OBSTETRICS IN GENERAL PRACTICE. MANAGEMENT OF MALPRESENTATIONS IN OBSTETRICS. Br Med J . 1964 May 16. 1(5393):1295-8. [QxMD MEDLINE Link] .

Campbell JM. Face presentation. Aust N Z J Obstet Gynaecol . 1965 Nov. 5(4):231-4. [QxMD MEDLINE Link] .

CHEN HY, WEI PY. Facial presentation and pelvic type; an analysis of twenty-one cases. J Int Coll Surg . 1960 Dec. 34:756-64. [QxMD MEDLINE Link] .

Copeland GN Jr, Nicks FI Jr, Christakos AC. Face and brow presentations. N C Med J . 1968 Dec. 29(12):507-10. [QxMD MEDLINE Link] .

Cruikshank DP, White CA. Obstetric malpresentations: twenty years' experience. Am J Obstet Gynecol . 1973 Aug 15. 116(8):1097-104. [QxMD MEDLINE Link] .

Cucco UP. Face presentation. Am J Obstet Gynecol . 1966 Apr 15. 94(8):1085-91. [QxMD MEDLINE Link] .

Cunningham FG, Gant NF, Leveno KJ et al. Abnormal Labor. Williams Obstetrics . 23 rd. 452-454.

DEDE JA, FRIEDMAN EA. FACE PRESENTATION. Am J Obstet Gynecol . 1963 Oct 15. 87:515-24. [QxMD MEDLINE Link] .

Duff P. Diagnosis and management of face presentation. Obstet Gynecol . 1981 Jan. 57(1):105-12. [QxMD MEDLINE Link] .

Gomez HE, Denner EH. Face presentation. Obstet Gynecol . 1956. 8:103-6.

GROENIG DC. Face presentation; analysis of thirty-seven cases at Louisville General Hospital. Obstet Gynecol . 1953 Nov. 2(5):495-9. [QxMD MEDLINE Link] .

Hankins GDV, Clark SL, Cunningham FG, Gilstrap LC. Operative Obstetrics: Forceps Delivery . Norwalk, Conn: Appleton & Lange; 1995. 168.

Hillman LM, Epperson JWW, Connally F. Face and brow presentation. Am J Obstet Gynecol . 1950. 59:831-42.

JACOBSON LJ, JOHNSON CE. Brow and face presentations. Am J Obstet Gynecol . 1962 Dec 15. 84:1881-6. [QxMD MEDLINE Link] .

Lauer AK, Rimmer SO. Eyelid laceration in a neonate by fetal monitoring spiral electrode. Am J Ophthalmol . 1998 May. 125(5):715-7. [QxMD MEDLINE Link] .

Magid R, Gillespie CF. Face and brow presentation. Obstet Gynecol . 1957. 9:450-7.

Miyashiro MJ, Mintz-Hittner HA. Penetrating ocular injury with a fetal scalp monitoring spiral electrode. Am J Ophthalmol . 1999 Oct. 128(4):526-8. [QxMD MEDLINE Link] .

Posner AC, Buch IM. Face and persistent brow presentations. Surg Gynecol Obstet . 1943. 77:618-30.

POSNER AC, COHN S. An analysis of 45 face presentations. Am J Obstet Gynecol . 1951 Sep. 62(3):592-9. [QxMD MEDLINE Link] .

Posner AC, Friedman S, Posner LB. Modern trends in the management of face and brow presentations. Surg Gynecol Obstet . 1957. 104:485-90.

POSNER LB, RUBIN EJ, POSNER AC. Face and brow presentations. A continuing study. Obstet Gynecol . 1963 Jun. 21:745-9. [QxMD MEDLINE Link] .

Prevedourakis CN. Face presentation. An analysis of 163 cases. Am J Obstet Gynecol . 1966 Apr 15. 94(8):1092-7. [QxMD MEDLINE Link] .

Reddock JW. Face Presentation. Am J Obstet Gynecol . 1948. 56:86-99.

Reinke T. Face presentation. Am J Obstet Gynecol . 1958. 66:1185-90.

Rudolph SJ. Face presentation. Am J Obstet Gynecol . 1947. 54:987-93.

Salzmann B, Soled M, Gilmour T. Face presentation. Obstet Gynecol . 1960. 16:106-12.

Scheer K, Nubar J. Variation of fetal presentation with gestational age. Am J Obstet Gynecol . 1976 May 15. 125(2):269-70. [QxMD MEDLINE Link] .

Schwartz Z, Dgani R, Lancet M. Face presentation. Aust N Z J Obstet Gynaecol . 1986 Aug. 26(3):172-6. [QxMD MEDLINE Link] .

TANCER ML, ROSANELLI P. Face and persistent brow presentations. Obstet Gynecol . 1957 Dec. 10(6):632-5. [QxMD MEDLINE Link] .

Contributor Information and Disclosures

Teresa Marino, MD Assistant Professor, Attending Physician, Division of Maternal-Fetal Medicine, Tufts Medical Center Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference Disclosure: Received salary from Medscape for employment. for: Medscape.

Carl V Smith, MD The Distinguished Chris J and Marie A Olson Chair of Obstetrics and Gynecology, Professor, Department of Obstetrics and Gynecology, Senior Associate Dean for Clinical Affairs, University of Nebraska Medical Center Carl V Smith, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists , American Institute of Ultrasound in Medicine , Association of Professors of Gynecology and Obstetrics , Central Association of Obstetricians and Gynecologists , Society for Maternal-Fetal Medicine , Council of University Chairs of Obstetrics and Gynecology , Nebraska Medical Association Disclosure: Nothing to disclose.

Chitra M Iyer, MD, Perinatologist, Obstetrix Medical Group, Fort Worth, Texas.

Chitra M Iyer, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists , Society of Maternal-Fetal Medicine .

Disclosure: Nothing to disclose.

What would you like to print?

  • Print this section
  • Print the entire contents of
  • Print the entire contents of article

Medscape Logo

  • Pulmonary Disease and Pregnancy
  • Renal Disease and Pregnancy
  • HIV in Pregnancy
  • Anemia and Thrombocytopenia in Pregnancy
  • Cardiovascular Disease and Pregnancy
  • Common Pregnancy Complaints and Questions
  • Transplantation and Pregnancy
  • Vitamin D Deficiency Linked to Bacterial Vaginosis in Pregnant Women
  • Pregnancy Intention and Health Behaviors: Results from the Central Pennsylvania Women's Health Study Cohort
  • Drug Interaction Checker
  • Pill Identifier
  • Calculators

ss-abdominal-pain

the presenting diameter in brow presentation

  • Physician Physician Board Reviews Physician Associate Board Reviews CME Lifetime CME Free CME
  • Student USMLE Step 1 USMLE Step 2 USMLE Step 3 COMLEX Level 1 COMLEX Level 2 COMLEX Level 3 96 Medical School Exams Student Resource Center NCLEX - RN NCLEX - LPN/LVN/PN 24 Nursing Exams
  • Nurse Practitioner APRN/NP Board Reviews CNS Certification Reviews CE - Nurse Practitioner FREE CE
  • Nurse RN Certification Reviews CE - Nurse FREE CE
  • Pharmacist Pharmacy Board Exam Prep CE - Pharmacist
  • Allied Allied Health Exam Prep Dentist Exams CE - Social Worker CE - Dentist
  • Point of Care
  • Free CME/CE

Delivery, Face and Brow Presentation

Introduction.

The term presentation describes the leading part of the fetus or the anatomical structure closest to the maternal pelvic inlet during labor. The presentation can roughly be divided into the following classifications: cephalic, breech, shoulder, and compound. Cephalic presentation is the most common and can be further subclassified as vertex, sinciput, brow, face, and chin. The most common presentation in term labor is the vertex, where the fetal neck is flexed to the chin, minimizing the head circumference.

Face presentation – an abnormal form of cephalic presentation where the presenting part is mentum. This typically occurs because of hyperextension of the neck and the occiput touching the fetal back. Incidence of face presentation is rare, accounting for approximately 1 in 600 of all presentations. [1] [2] [3]

In brow presentation, the neck is not extended as much as in face presentation, and the leading part is the area between the anterior fontanelle and the orbital ridges. Brow presentation is considered the rarest of all malpresentation with a prevalence of 1 in 500 to 1 in 4000 deliveries. [3]

Both face and brow presentations occur due to extension of the fetal neck instead of flexion; therefore, conditions that would lead to hyperextension or prevent flexion of the fetal neck can all contribute to face or brow presentation. These risk factors may be related to either the mother or the fetus. Maternal risk factors are preterm delivery, contracted maternal pelvis, platypelloid pelvis, multiparity, previous cesarean section, black race. Fetal risk factors include anencephaly, multiple loops of cord around the neck, masses of the neck, macrosomia, polyhydramnios. [2] [4] [5]

These malpresentations are usually diagnosed during the second stage of labor when performing a digital examination. It is possible to palpate orbital ridges, nose, malar eminences, mentum, mouth, gums, and chin in face presentation. Based on the position of the chin, face presentation can be further divided into mentum anterior, posterior, or transverse. In brow presentation, anterior fontanelle and face can be palpated except for the mouth and the chin. Brow presentation can then be further described based on the position of the anterior fontanelle as frontal anterior, posterior, or transverse.

Diagnosing the exact presentation can be challenging, and face presentation may be misdiagnosed as frank breech. To avoid any confusion, a bedside ultrasound scan can be performed. [6]  The ultrasound imaging can show a reduced angle between the occiput and the spine or, the chin is separated from the chest. However, ultrasound does not provide much predicting value in the outcome of the labor. [7]

Anatomy and Physiology

Register for free and read the full article, learn more about a subscription to statpearls point-of-care.

Before discussing the mechanism of labor in the face or brow presentation, it is crucial to highlight some anatomical landmarks and their measurements. 

Planes and Diameters of the Pelvis

The three most important planes in the female pelvis are the pelvic inlet, mid pelvis, and pelvic outlet. 

Four diameters can describe the pelvic inlet: anteroposterior, transverse, and two obliques. Furthermore, based on the different landmarks on the pelvic inlet, there are three different anteroposterior diameters, named conjugates: true conjugate, obstetrical conjugate, and diagonal conjugate. Only the latter can be measured directly during the obstetric examination. The shortest of these three diameters is obstetrical conjugate, which measures approximately 10.5 cm and is a distance between the sacral promontory and 1 cm below the upper border of the symphysis pubis. This measurement is clinically significant as the fetal head must pass through this diameter during the engagement phase. The transverse diameter measures about 13.5cm and is the widest distance between the innominate line on both sides. 

The shortest distance in the mid pelvis is the interspinous diameter and usually is only about 10 cm. 

Fetal Skull Diameters

There are six distinguished longitudinal fetal skull diameters:

  • Suboccipito-bregmatic: from the center of anterior fontanelle (bregma) to the occipital protuberance, measuring 9.5 cm. This is the presenting diameter in vertex presentation. 
  • Suboccipito-frontal: from the anterior part of bregma to the occipital protuberance, measuring 10 cm 
  • Occipito-frontal: from the root of the nose to the most prominent part of the occiput, measuring 11.5cm
  • Submento-bregmatic: from the center of the bregma to the angle of the mandible, measuring 9.5 cm. This is the presenting diameter in face presentation where the neck is hyperextended. 
  • Submento-vertical: from the midpoint between fontanelles and the angle of the mandible, measuring 11.5cm 
  • Occipito-mental: from the midpoint between fontanelles and the tip of the chin, measuring 13.5 cm. It is the presenting diameter in brow presentation. 

Cardinal Movements of Normal Labor

  • Neck flexion
  • Internal rotation
  • Extension (delivers head)
  • External rotation (Restitution)
  • Expulsion (delivery of anterior and posterior shoulders)

Some of the key movements are not possible in the face or brow presentations.  

Based on the information provided above, it is obvious that labor will be arrested in brow presentation unless it spontaneously changes to face or vertex, as the occipito-mental diameter of the fetal head is significantly wider than the smallest diameter of the female pelvis. Face presentation can, however, be delivered vaginally, and further mechanisms of face delivery will be explained in later sections.

Indications

As mentioned previously, spontaneous vaginal delivery can be successful in face presentation. However, the main indication for vaginal delivery in such circumstances would be a maternal choice. It is crucial to have a thorough conversation with a mother, explaining the risks and benefits of vaginal delivery with face presentation and a cesarean section. Informed consent and creating a rapport with the mother is an essential aspect of safe and successful labor.

Contraindications

Vaginal delivery of face presentation is contraindicated if the mentum is lying posteriorly or is in a transverse position. In such a scenario, the fetal brow is pressing against the maternal symphysis pubis, and the short fetal neck, which is already maximally extended, cannot span the surface of the maternal sacrum. In this position, the diameter of the head is larger than the maternal pelvis, and it cannot descend through the birth canal. Therefore the cesarean section is recommended as the safest mode of delivery for mentum posterior face presentations. 

Attempts to manually convert face presentation to vertex, manual or forceps rotation of the persistent posterior chin to anterior are contraindicated as they can be dangerous.

Persistent brow presentation itself is a contraindication for vaginal delivery unless the fetus is significantly small or the maternal pelvis is large.

Continuous electronic fetal heart rate monitoring is recommended for face and brow presentations, as heart rate abnormalities are common in these scenarios. One study found that only 14% of the cases with face presentation had no abnormal traces on the cardiotocograph. [8] It is advised to use external transducer devices to prevent damage to the eyes. When internal monitoring is inevitable, it is suggested to place monitoring devices on bony parts carefully. 

People who are usually involved in the delivery of face/ brow presentation are:

  • Experienced midwife, preferably looking after laboring woman 1:1
  • Senior obstetrician 
  • Neonatal team - in case of need for resuscitation 
  • Anesthetic team - to provide necessary pain control (e.g., epidural)
  • Theatre team  - in case of failure to progress and an emergency cesarean section will be required.

Preparation

No specific preparation is required for face or brow presentation. However, it is essential to discuss the labor options with the mother and birthing partner and inform members of the neonatal, anesthetic, and theatre co-ordinating teams.

Technique or Treatment

Mechanism of Labor in Face Presentation

During contractions, the pressure exerted by the fundus of the uterus on the fetus and pressure of amniotic fluid initiate descent. During this descent, the fetal neck extends instead of flexing. The internal rotation determines the outcome of delivery, if the fetal chin rotates posteriorly, vaginal delivery would not be possible, and cesarean section is permitted. The approach towards mentum-posterior delivery should be individualized, as the cases are rare. Expectant management is acceptable in multiparous women with small fetuses, as a spontaneous mentum-anterior rotation can occur. However, there should be a low threshold for cesarean section in primigravida women or women with large fetuses.

When the fetal chin is rotated towards maternal symphysis pubis as described as mentum-anterior; in these cases further descend through the vaginal canal continues with approximately 73% cases deliver spontaneously. [9] Fetal mentum presses on the maternal symphysis pubis, and the head is delivered by flexion. The occiput is pointing towards the maternal back, and external rotation happens. Shoulders are delivered in the same manner as in vertex delivery.

Mechanism of Labor in Brow Presentation

As this presentation is considered unstable, it is usually converted into a face or an occiput presentation. Due to the cephalic diameter being wider than the maternal pelvis, the fetal head cannot engage; thus, brow delivery cannot take place. Unless the fetus is small or the pelvis is very wide, the prognosis for vaginal delivery is poor. With persistent brow presentation, a cesarean section is required for safe delivery.

Complications

As the cesarean section is becoming a more accessible mode of delivery in malpresentations, the incidence of maternal and fetal morbidity and mortality during face presentation has dropped significantly. [10]

However, there are still some complications associated with the nature of labor in face presentation. Due to the fetal head position, it is more challenging for the head to engage in the birth canal and descend, resulting in prolonged labor.

Prolonged labor itself can provoke foetal distress and arrhythmias. If the labor arrests or signs of fetal distress appear on CTG, the recommended next step in management is an emergency cesarean section, which in itself carries a myriad of operative and post-operative complications.

Finally, due to the nature of the fetal position and prolonged duration of labor in face presentation, neonates develop significant edema of the skull and face. Swelling of the fetal airway may also be present, resulting in respiratory distress after birth and possible intubation.

Clinical Significance

During vertex presentation, the fetal head flexes, bringing the chin to the chest, forming the smallest possible fetal head diameter, measuring approximately 9.5cm. With face and brow presentation, the neck hyperextends, resulting in greater cephalic diameters. As a result, the fetal head will engage later, and labor will progress more slowly. Failure to progress in labor is also more common in both presentations compared to vertex presentation.

Furthermore, when the fetal chin is in a posterior position, this prevents further flexion of the fetal neck, as browns are pressing on the symphysis pubis. As a result, descend through the birth canal is impossible. Such presentation is considered undeliverable vaginally and requires an emergency cesarean section.

Manual attempts to change face presentation to vertex, manual or forceps rotation to mentum anterior are considered dangerous and are discouraged.

Enhancing Healthcare Team Outcomes

A multidisciplinary team of healthcare experts supports the woman and her child during labor and the perinatal period. For a face or brow presentation to be appropriately diagnosed, an experienced midwife and obstetrician must be involved in the vaginal examination and labor monitoring. As fetal anomalies, such as anencephaly or goiter, can contribute to face presentation, sonographers experienced in antenatal scanning should also be involved in the care. It is advised to inform the anesthetic and neonatal teams in advance of the possible need for emergency cesarean section and resuscitation of the neonate. [11] [12]

Gardberg M,Leonova Y,Laakkonen E, Malpresentations--impact on mode of delivery. Acta obstetricia et gynecologica Scandinavica. 2011 May;     [PubMed PMID: 21501123]

Tapisiz OL,Aytan H,Altinbas SK,Arman F,Tuncay G,Besli M,Mollamahmutoglu L,Danışman N, Face presentation at term: a forgotten issue. The journal of obstetrics and gynaecology research. 2014 Jun;     [PubMed PMID: 24888918]

Zayed F,Amarin Z,Obeidat B,Obeidat N,Alchalabi H,Lataifeh I, Face and brow presentation in northern Jordan, over a decade of experience. Archives of gynecology and obstetrics. 2008 Nov;     [PubMed PMID: 18283473]

Bashiri A,Burstein E,Bar-David J,Levy A,Mazor M, Face and brow presentation: independent risk factors. The journal of maternal-fetal     [PubMed PMID: 18570114]

Shaffer BL,Cheng YW,Vargas JE,Laros RK Jr,Caughey AB, Face presentation: predictors and delivery route. American journal of obstetrics and gynecology. 2006 May;     [PubMed PMID: 16647888]

Bellussi F,Ghi T,Youssef A,Salsi G,Giorgetta F,Parma D,Simonazzi G,Pilu G, The use of intrapartum ultrasound to diagnose malpositions and cephalic malpresentations. American journal of obstetrics and gynecology. 2017 Dec;     [PubMed PMID: 28743440]

Ghi T,Eggebø T,Lees C,Kalache K,Rozenberg P,Youssef A,Salomon LJ,Tutschek B, ISUOG Practice Guidelines: intrapartum ultrasound. Ultrasound in obstetrics     [PubMed PMID: 29974596]

Benedetti TJ,Lowensohn RI,Truscott AM, Face presentation at term. Obstetrics and gynecology. 1980 Feb;     [PubMed PMID: 7352081]

Ducarme G,Ceccaldi PF,Chesnoy V,Robinet G,Gabriel R, [Face presentation: retrospective study of 32 cases at term]. Gynecologie, obstetrique     [PubMed PMID: 16630740]

Cruikshank DP,Cruikshank JE, Face and brow presentation: a review. Clinical obstetrics and gynecology. 1981 Jun;     [PubMed PMID: 7307363]

Domingues AP,Belo A,Moura P,Vieira DN, Medico-legal litigation in Obstetrics: a characterization analysis of a decade in Portugal. Revista brasileira de ginecologia e obstetricia : revista da Federacao Brasileira das Sociedades de Ginecologia e Obstetricia. 2015 May;     [PubMed PMID: 26107576]

. Intrapartum care for healthy women and babies. 2022 Dec 14:():     [PubMed PMID: 32212591]

Use the mouse wheel to zoom in and out, click and drag to pan the image

Book cover

Labour and Delivery pp 99–105 Cite as

Face Presentation

  • Shubhra Agarwal 2 &
  • Suchitra Pandit 3  
  • First Online: 02 August 2023

370 Accesses

Face presentation is defined as a cephalic presentation in which the presenting part is face and it occurs due to factors that lead to extension of of fetal head. It is a rare obstetric presentation and may not be encountered even in the entire carrier of an obstetrician.

  • Face presentation
  • Active phase of labor
  • Prematurity
  • Deflexed head
  • Congenital malformations
  • Dolichocephalic skull
  • Mento-anterior
  • Crichton’s method

This is a preview of subscription content, log in via an institution .

Buying options

  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
  • Available as EPUB and PDF
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Shaffer BL. Face presentation: predictors and delivery route. Am J Obstet Gynecol. 2006;194:e10–2.

Article   PubMed   Google Scholar  

Schwartz Z, Dgani R, Lancet M, Kessler I. Face presentation. Aust N Z J Obstet Gynaecol. 1986;26:172–6.

Article   CAS   PubMed   Google Scholar  

Westgren M, et al. Face presentation in modern obstetrics-a study with special reference to fetal long term morbidity. Z Geburtshilfe Perinatol. 1984;188(2):87–9.

CAS   PubMed   Google Scholar  

Download references

Author information

Authors and affiliations.

Department of Obstetrics and Gynaecology, TMMC&RC, Moradabad, India

Shubhra Agarwal

Department of Obstetrics and Gynaecology, Surya Hospital, Mumbai, India

Suchitra Pandit

You can also search for this author in PubMed   Google Scholar

Editor information

Editors and affiliations.

Department of Obstetrics and Gynecology, Sarojini Naidu Medical College, Agra, Uttar Pradesh, India

Ruchika Garg

Rights and permissions

Reprints and permissions

Copyright information

© 2023 The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

About this chapter

Cite this chapter.

Agarwal, S., Pandit, S. (2023). Face Presentation. In: Garg, R. (eds) Labour and Delivery. Springer, Singapore. https://doi.org/10.1007/978-981-19-6145-8_6

Download citation

DOI : https://doi.org/10.1007/978-981-19-6145-8_6

Published : 02 August 2023

Publisher Name : Springer, Singapore

Print ISBN : 978-981-19-6144-1

Online ISBN : 978-981-19-6145-8

eBook Packages : Medicine Medicine (R0)

Share this chapter

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

  • Publish with us

Policies and ethics

  • Find a journal
  • Track your research

Europe PMC requires Javascript to function effectively.

Either your web browser doesn't support Javascript or it is currently turned off. In the latter case, please turn on Javascript support in your web browser and reload this page.

Search life-sciences literature ( 43,693,114 articles, preprints and more)

  • Free full text
  • Similar Articles

Delivery, Face and Brow Presentation

Author information, affiliations.

  • Makajeva J 1

Study Guide from StatPearls Publishing, Treasure Island (FL) , 24 Feb 2021 PMID: 33620804 

Books & documents Free full text in Europe PMC

Abstract 

Free full text .

StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-.

Cover of StatPearls

StatPearls [Internet].

Bulk download.

  • Bulk download StatPearls data from FTP

Julija Makajeva ; Mohsina Ashraf .

Last Update: January 9, 2023 .

Continuing Education Activity

Face and brow presentation is a malpresentation during labor when the presenting part is either the face or, in the case of brow presentation, it is the area between the orbital ridge and the anterior fontanelle. This activity reviews the evaluation and management of these two presentations and explains the role of the interprofessional team in managing delivery safely for both the mother and the baby.

Objectives:

  • Describe the mechanism of labor in the face and brow presentation.
  • Summarize potential maternal and fetal complications during the face and brow presentations.
  • Review different management approaches for the face and brow presentation.
  • Outline some interprofessional strategies that will improve patient outcomes in delivery cases with face and brow presentation issues.

Introduction

The term presentation describes the leading part of the fetus or the anatomical structure closest to the maternal pelvic inlet during labor. The presentation can roughly be divided into the following classifications: cephalic, breech, shoulder, and compound. Cephalic presentation is the most common and can be further subclassified as vertex, sinciput, brow, face, and chin. The most common presentation in term labor is the vertex, where the fetal neck is flexed to the chin, minimizing the head circumference.

Face presentation – an abnormal form of cephalic presentation where the presenting part is mentum. This typically occurs because of hyperextension of the neck and the occiput touching the fetal back. Incidence of face presentation is rare, accounting for approximately 1 in 600 of all presentations. [1] [2] [3]

In brow presentation, the neck is not extended as much as in face presentation, and the leading part is the area between the anterior fontanelle and the orbital ridges. Brow presentation is considered the rarest of all malpresentation with a prevalence of 1 in 500 to 1 in 4000 deliveries. [3]

Both face and brow presentations occur due to extension of the fetal neck instead of flexion; therefore, conditions that would lead to hyperextension or prevent flexion of the fetal neck can all contribute to face or brow presentation. These risk factors may be related to either the mother or the fetus. Maternal risk factors are preterm delivery, contracted maternal pelvis, platypelloid pelvis, multiparity, previous cesarean section, black race. Fetal risk factors include anencephaly, multiple loops of cord around the neck, masses of the neck, macrosomia, polyhydramnios. [2] [4] [5]

These malpresentations are usually diagnosed during the second stage of labor when performing a digital examination. It is possible to palpate orbital ridges, nose, malar eminences, mentum, mouth, gums, and chin in face presentation. Based on the position of the chin, face presentation can be further divided into mentum anterior, posterior, or transverse. In brow presentation, anterior fontanelle and face can be palpated except for the mouth and the chin. Brow presentation can then be further described based on the position of the anterior fontanelle as frontal anterior, posterior, or transverse.

Diagnosing the exact presentation can be challenging, and face presentation may be misdiagnosed as frank breech. To avoid any confusion, a bedside ultrasound scan can be performed. [6]  The ultrasound imaging can show a reduced angle between the occiput and the spine or, the chin is separated from the chest. However, ultrasound does not provide much predicting value in the outcome of the labor. [7]

Anatomy and Physiology

Before discussing the mechanism of labor in the face or brow presentation, it is crucial to highlight some anatomical landmarks and their measurements. 

Planes and Diameters of the Pelvis

The three most important planes in the female pelvis are the pelvic inlet, mid pelvis, and pelvic outlet. 

Four diameters can describe the pelvic inlet: anteroposterior, transverse, and two obliques. Furthermore, based on the different landmarks on the pelvic inlet, there are three different anteroposterior diameters, named conjugates: true conjugate, obstetrical conjugate, and diagonal conjugate. Only the latter can be measured directly during the obstetric examination. The shortest of these three diameters is obstetrical conjugate, which measures approximately 10.5 cm and is a distance between the sacral promontory and 1 cm below the upper border of the symphysis pubis. This measurement is clinically significant as the fetal head must pass through this diameter during the engagement phase. The transverse diameter measures about 13.5cm and is the widest distance between the innominate line on both sides. 

The shortest distance in the mid pelvis is the interspinous diameter and usually is only about 10 cm. 

Fetal Skull Diameters

There are six distinguished longitudinal fetal skull diameters:

  • Suboccipito-bregmatic: from the center of anterior fontanelle (bregma) to the occipital protuberance, measuring 9.5 cm. This is the presenting diameter in vertex presentation. 
  • Suboccipito-frontal: from the anterior part of bregma to the occipital protuberance, measuring 10 cm 
  • Occipito-frontal: from the root of the nose to the most prominent part of the occiput, measuring 11.5cm
  • Submento-bregmatic: from the center of the bregma to the angle of the mandible, measuring 9.5 cm. This is the presenting diameter in face presentation where the neck is hyperextended. 
  • Submento-vertical: from the midpoint between fontanelles and the angle of the mandible, measuring 11.5cm 
  • Occipito-mental: from the midpoint between fontanelles and the tip of the chin, measuring 13.5 cm. It is the presenting diameter in brow presentation. 

Cardinal Movements of Normal Labor

  • Neck flexion
  • Internal rotation
  • Extension (delivers head)
  • External rotation (Restitution)
  • Expulsion (delivery of anterior and posterior shoulders)

Some of the key movements are not possible in the face or brow presentations.  

Based on the information provided above, it is obvious that labor will be arrested in brow presentation unless it spontaneously changes to face or vertex, as the occipito-mental diameter of the fetal head is significantly wider than the smallest diameter of the female pelvis. Face presentation can, however, be delivered vaginally, and further mechanisms of face delivery will be explained in later sections.

Indications

As mentioned previously, spontaneous vaginal delivery can be successful in face presentation. However, the main indication for vaginal delivery in such circumstances would be a maternal choice. It is crucial to have a thorough conversation with a mother, explaining the risks and benefits of vaginal delivery with face presentation and a cesarean section. Informed consent and creating a rapport with the mother is an essential aspect of safe and successful labor.

Contraindications

Vaginal delivery of face presentation is contraindicated if the mentum is lying posteriorly or is in a transverse position. In such a scenario, the fetal brow is pressing against the maternal symphysis pubis, and the short fetal neck, which is already maximally extended, cannot span the surface of the maternal sacrum. In this position, the diameter of the head is larger than the maternal pelvis, and it cannot descend through the birth canal. Therefore the cesarean section is recommended as the safest mode of delivery for mentum posterior face presentations. 

Attempts to manually convert face presentation to vertex, manual or forceps rotation of the persistent posterior chin to anterior are contraindicated as they can be dangerous.

Persistent brow presentation itself is a contraindication for vaginal delivery unless the fetus is significantly small or the maternal pelvis is large.

Continuous electronic fetal heart rate monitoring is recommended for face and brow presentations, as heart rate abnormalities are common in these scenarios. One study found that only 14% of the cases with face presentation had no abnormal traces on the cardiotocograph. [8] It is advised to use external transducer devices to prevent damage to the eyes. When internal monitoring is inevitable, it is suggested to place monitoring devices on bony parts carefully. 

People who are usually involved in the delivery of face/ brow presentation are:

  • Experienced midwife, preferably looking after laboring woman 1:1
  • Senior obstetrician 
  • Neonatal team - in case of need for resuscitation 
  • Anesthetic team - to provide necessary pain control (e.g., epidural)
  • Theatre team  - in case of failure to progress and an emergency cesarean section will be required.

Preparation

No specific preparation is required for face or brow presentation. However, it is essential to discuss the labor options with the mother and birthing partner and inform members of the neonatal, anesthetic, and theatre co-ordinating teams.

Technique or Treatment

Mechanism of Labor in Face Presentation

During contractions, the pressure exerted by the fundus of the uterus on the fetus and pressure of amniotic fluid initiate descent. During this descent, the fetal neck extends instead of flexing. The internal rotation determines the outcome of delivery, if the fetal chin rotates posteriorly, vaginal delivery would not be possible, and cesarean section is permitted. The approach towards mentum-posterior delivery should be individualized, as the cases are rare. Expectant management is acceptable in multiparous women with small fetuses, as a spontaneous mentum-anterior rotation can occur. However, there should be a low threshold for cesarean section in primigravida women or women with large fetuses.

When the fetal chin is rotated towards maternal symphysis pubis as described as mentum-anterior; in these cases further descend through the vaginal canal continues with approximately 73% cases deliver spontaneously. [9] Fetal mentum presses on the maternal symphysis pubis, and the head is delivered by flexion. The occiput is pointing towards the maternal back, and external rotation happens. Shoulders are delivered in the same manner as in vertex delivery.

Mechanism of Labor in Brow Presentation

As this presentation is considered unstable, it is usually converted into a face or an occiput presentation. Due to the cephalic diameter being wider than the maternal pelvis, the fetal head cannot engage; thus, brow delivery cannot take place. Unless the fetus is small or the pelvis is very wide, the prognosis for vaginal delivery is poor. With persistent brow presentation, a cesarean section is required for safe delivery.

Complications

As the cesarean section is becoming a more accessible mode of delivery in malpresentations, the incidence of maternal and fetal morbidity and mortality during face presentation has dropped significantly. [10]

However, there are still some complications associated with the nature of labor in face presentation. Due to the fetal head position, it is more challenging for the head to engage in the birth canal and descend, resulting in prolonged labor.

Prolonged labor itself can provoke foetal distress and arrhythmias. If the labor arrests or signs of fetal distress appear on CTG, the recommended next step in management is an emergency cesarean section, which in itself carries a myriad of operative and post-operative complications.

Finally, due to the nature of the fetal position and prolonged duration of labor in face presentation, neonates develop significant edema of the skull and face. Swelling of the fetal airway may also be present, resulting in respiratory distress after birth and possible intubation.

Clinical Significance

During vertex presentation, the fetal head flexes, bringing the chin to the chest, forming the smallest possible fetal head diameter, measuring approximately 9.5cm. With face and brow presentation, the neck hyperextends, resulting in greater cephalic diameters. As a result, the fetal head will engage later, and labor will progress more slowly. Failure to progress in labor is also more common in both presentations compared to vertex presentation.

Furthermore, when the fetal chin is in a posterior position, this prevents further flexion of the fetal neck, as browns are pressing on the symphysis pubis. As a result, descend through the birth canal is impossible. Such presentation is considered undeliverable vaginally and requires an emergency cesarean section.

Manual attempts to change face presentation to vertex, manual or forceps rotation to mentum anterior are considered dangerous and are discouraged.

Enhancing Healthcare Team Outcomes

A multidisciplinary team of healthcare experts supports the woman and her child during labor and the perinatal period. For a face or brow presentation to be appropriately diagnosed, an experienced midwife and obstetrician must be involved in the vaginal examination and labor monitoring. As fetal anomalies, such as anencephaly or goiter, can contribute to face presentation, sonographers experienced in antenatal scanning should also be involved in the care. It is advised to inform the anesthetic and neonatal teams in advance of the possible need for emergency cesarean section and resuscitation of the neonate. [11] [12]

Review Questions

  • Access free multiple choice questions on this topic.
  • Comment on this article.

Disclosure: Julija Makajeva declares no relevant financial relationships with ineligible companies.

Disclosure: Mohsina Ashraf declares no relevant financial relationships with ineligible companies.

This book is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ), which permits others to distribute the work, provided that the article is not altered or used commercially. You are not required to obtain permission to distribute this article, provided that you credit the author and journal.

Similar Articles 

To arrive at the top five similar articles we use a word-weighted algorithm to compare words from the Title and Abstract of each citation.

Sonographic diagnosis of fetal head deflexion and the risk of cesarean delivery.

Bellussi F , Livi A , Cataneo I , Salsi G , Lenzi J , Pilu G

Am J Obstet Gynecol MFM , 2(4):100217, 18 Aug 2020

Cited by: 0 articles | PMID: 33345926

Sonographic evaluation of the fetal head position and attitude during labor.

Ghi T , Dall'Asta A

Am J Obstet Gynecol , S0002-9378(22)00449-5, 06 Jul 2022

Cited by: 0 articles | PMID: 37278991

Stages of Labor

Hutchison J , Mahdy H , Hutchison J

StatPearls Publishing, Treasure Island (FL) , 24 Jul 2019

Cited by: 1 article | PMID: 31335010

Leopold Maneuvers

Superville SS , Siccardi MA

StatPearls Publishing, Treasure Island (FL) , 19 Aug 2020

Cited by: 0 articles | PMID: 32809649

Labor with abnormal presentation and position.

Stitely ML , Gherman RB

Obstet Gynecol Clin North Am , 32(2):165-179, 01 Jun 2005

Cited by: 5 articles | PMID: 15899353

Europe PMC is part of the ELIXIR infrastructure

Academia.edu no longer supports Internet Explorer.

To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to  upgrade your browser .

Enter the email address you signed up with and we'll email you a reset link.

  • We're Hiring!
  • Help Center

paper cover thumbnail

PHYSIOLOGY AND MANAGEMENT OF ABNORMAL LABOUR. NOTES ON FACE PRESENTATION, BROW PRESENTATION AND TRANSVERSE LIE PRESENTATION

Profile image of Dr. Richard Nkrumah

At term, the fetal spine typically lies along the longitudinal axis of the uterus, as this lie best accommodates the relatively long torso of the fetus within the uterine cavity and positions the fetus for egress into the birth canal. The fetus usually maneuvers to accommodate the breech and flexed legs in the broad uterine fundus and the head in the narrower lower uterine segment. This seems to allow the best fit in the available intrauterine space. During labor, presentation is further defined by the part of the fetus that leads into the birth canal: vertex (occiput), face, brow, breech (frank, footling, complete), shoulder, or compound (a limb and head or breech). Fetuses in transverse or oblique lie have no presenting part descending into the birth canal.

RELATED TOPICS

  •   We're Hiring!
  •   Help Center
  • Find new research papers in:
  • Health Sciences
  • Earth Sciences
  • Cognitive Science
  • Mathematics
  • Computer Science
  • Academia ©2024

Fastest Obstetric, Gynecology and Pediatric Insight Engine

  • Abdominal Key
  • Anesthesia Key
  • Basicmedical Key
  • Otolaryngology & Ophthalmology
  • Musculoskeletal Key
  • Obstetric, Gynecology and Pediatric
  • Oncology & Hematology
  • Plastic Surgery & Dermatology
  • Clinical Dentistry
  • Radiology Key
  • Thoracic Key
  • Veterinary Medicine
  • Gold Membership

Malpresentations

Key Abbreviations Abdominal diameter AD American College of Obstetricians and Gynecologists ACOG Amniotic fluid index AFI Anteroposterior AP Biparietal diameter BPD Cerebral palsy CP Combined spinal-epidural CSE Computed tomography CT Confidence interval CI External cephalic version ECV Ex utero intrapartum treatment  EXIT Fetal heart rate FHR Internal podalic version IPV Magnetic resonance imaging MRI Occipitofrontal diameter OFD Odds ratio OR Perinatal mortality rate PMR Periventricular leukomalacia PVL Preterm premature rupture of the membranes PPROM Relative risk RR Term breech trial TBT Near term or during labor, the fetus normally assumes a vertical orientation, or lie, and a cephalic presentation, with the flexed fetal vertex presenting to the pelvis ( Fig. 17-1 ). However, in about 3% to 5% of singleton gestations at term, an abnormal lie, presentation, or flexed attitude occurs; such deviations constitute fetal malpresentations. The word malpresentation suggests the possibility of adverse consequences, and malpresentation is often associated with increased risk to both the mother and the fetus. In the early twentieth century, mal­presentation often led to a variety of maneuvers intended to facilitate vaginal delivery, including destructive operations lead­ing, predictably, to fetal death. Later, manual or instrumented attempts to convert the malpresenting fetus to a more favorable orientation were devised. Internal podalic version (IPV) followed by a complete breech extraction was once advocated as a solution to many malpresentation situations. However, like with most manipulative efforts to achieve vaginal delivery, IPV was associated with high fetal and maternal morbidity and mortality rates and has been largely abandoned. In contemporary practice, cesarean delivery has become the recommended mode of delivery in the malpresenting fetus. FIG 17-1 Frontal view of a fetus in a longitudinal lie with fetal vertex flexed on the neck. Clinical Circumstances Associated with Malpresentation Generally, factors associated with malpresentation include (1) diminished vertical polarity of the uterine cavity, (2) increased or decreased fetal mobility, (3) obstructed pelvic inlet, (4) fetal malformation, and (5) prematurity. The association of great parity with malpresentation is presumably related to laxity of maternal abdominal musculature and resultant loss of the normal vertical orientation of the uterine cavity. Placentation either high in the fundus or low in the pelvis ( Fig. 17-2 ) is another factor that diminishes the likelihood of a fetus assuming a longitudinal axis. Uterine myomata, intrauterine synechiae, and müllerian duct fusion abnormalities such as a septate uterus or uterine didelphys are similarly associated with a higher than expected rate of malpresentation. Because both prematurity and polyhydramnios permit increased fetal mobility, the probability of a noncephalic presentation is greater if preterm labor or rupture of the membranes occurs. Furthermore, preterm birth involves a fetus that is small relative to the maternal pelvis; therefore engagement and descent with labor or rupture of the membranes can occur despite a malpresentation. In contrast, conditions such as chromosomal aneuploidies, congenital myotonic dystrophy, joint contractures from various etiologies, arthrogryposis, oligohydramnios, and fetal neurologic dysfunction that result in decreased fetal muscle tone, strength, or activity are also associated with an increased incidence of fetal malpresentation. Finally, the cephalopelvic disproportion associated with severe fetal hydrocephalus or with a contracted maternal pelvis may be implicated as an etiology of malpresentation because normal engagement of the fetal head is prevented. FIG 17-2 Either the high fundal or low implantation of the placenta, as illustrated here, would normally be in the vertical orientation of the intrauterine cavity and increase the probability of a malpresentation. Abnormal Axial Lie The fetal lie indicates the orientation of the fetal spine relative to the spine of the mother. The normal fetal lie is longitudinal and by itself does not indicate whether the presentation is cephalic or breech. If the fetal spine or long axis crosses that of the mother, the fetus may be said to occupy a transverse or oblique lie ( Fig. 17-3 ), which may cause an arm, foot, or shoulder to be the presenting part ( Fig. 17-4 ). The lie may be termed unstable if the fetal membranes are intact and fetal mobility is increased, which results in frequent changes of lie and/or presentation. FIG 17-3 A fetus may lie on a longitudinal, oblique, or transverse axis, as illustrated. The lie does not indicate whether the vertex or the breech is closest to the cervix. FIG 17-4 This fetus lies in an oblique axis with an arm prolapsing. Abnormal fetal lie is diagnosed in approximately 1 in 300 cases, or 0.33% of pregnancies at term. Prematurity is often a factor, with abnormal lie reported to occur in about 2% of pregnancies at 32 weeks’ gestation—six times the rate found at term. Persistence of a transverse, oblique, or unstable lie beyond 37 weeks’ gestation requires a systematic clinical assessment and a plan for management; this is because rupture of the membranes without a fetal part filling the inlet of the pelvis poses an increased risk of cord prolapse, fetal compromise, and maternal morbidity if neglected. As noted, great parity, prematurity, contraction or deformity of the maternal pelvis, and abnormal placentation are the most commonly reported clinical factors associated with abnormal lie; however, it often happens that none of these factors are present. In fact, any condition that alters the normal vertical polarity of the intrauterine cavity will predispose to abnormal lie. Diagnosis of the abnormal lie may be made by palpation using Leopold maneuvers or by vaginal examination verified by ultrasound. Whereas routine use of Leopold maneuvers may be helpful, Thorp and colleagues found the sensitivity of Leopold maneuvers for the detection of malpresentation to be only 28%, and the positive predictive value was only 24% compared with immediate ultrasound verification. Others have observed prenatal detection in as few as 41% of cases before labor. Adaptations have been made to the Leopold maneuvers that may improve detection of an abnormal lie or presentation. The Sharma modified Leopold maneuver and the Sharma right and left lateral maneuvers in the original report demonstrated improved diagnostic accuracy; they detected vertex presenting occipitoanterior (95% vs. 84.4%, P = .04), posterior presentations (96.3% vs. 66.6%, P = .00012), and breech presentations correctly more often than with traditional Leopold maneuvers. These maneuvers use the forearms in addition to the hands and fingers. As with any abdominal palpation technique, limitations on accuracy are to be expected in the obese patient and in a patient with uterine myomata. The ready availability of ultrasound in most clinical settings is of benefit, and its use can obviate the vagaries of the abdominal palpation techniques. In all situations, early diagnosis of malpresentation is of benefit . A reported fetal loss rate of 9.2% with an early diagnosis, versus a loss rate of 27.5% with a delayed diagnosis, indicates that early diagnosis improves fetal outcome. Reported perinatal mortality rates for unstable or transverse lie (corrected for lethal malformations and extreme prema­turity) vary from 3.9% to 24%, with maternal mortality as high as 10%. Maternal deaths are usually related to infection after premature rupture of membranes (PROM), hemorrhage secondary to abnormal placentation, complications of operative intervention for cephalopelvic disproportion, or traumatic delivery. Fetal loss of phenotypically and chromosomally normal gestations at ages considered to be viable is primarily associated with delayed interventions, prolapsed cord, or traumatic delivery. Cord prolapse occurs 20 times as often with abnormal lie as it does with a cephalic presentation. Management of a Singleton Gestation Safe vaginal delivery of a fetus from an abnormal axial lie is not generally possible. A search for the etiology of the malpresentation is always indicated. A transverse/oblique or unstable lie late in the third trimester necessitates ultrasound examination to exclude a major fetal malformation and abnormal placentation. Fortunately, most cases of major fetal anomalies or abnormal placentation can now be diagnosed long before the third trimester. Phelan and colleagues reported 29 patients with transverse lie diagnosed at or beyond 37 weeks’ gestation and managed expectantly, and 83% (24 of 29) spontaneously converted to breech (9 of 24) or vertex (15 of 24) before labor; however, the overall cesarean delivery rate was 45%, with two cases of cord prolapse, one uterine rupture, and one neonatal death. External cephalic version (ECV) is recommended at 36 to 37 weeks to help diminish the risk of adverse outcome. In cases of an abnormal lie, the risk of fetal death varies with the obstetric intervention. Fetal mortality should approach zero for cesarean birth but has been reported to be as high as 10% in older reports and between 25% and 90% when IPV and breech extraction are performed. ECV has been found to be safe and relatively efficacious and is further discussed later in this chapter. If external version is unsuccessful or unavailable, if spontaneous rupture of the membranes occurs, or if active labor has begun with an abnormal lie, cesarean delivery is the treatment of choice for the potentially viable infant. There is no place for IPV and breech extraction in the management of transverse or oblique lie or in an unstable presentation in a singleton pregnancy because of the unacceptably high rate of fetal and maternal complications. A persistent abnormal axial lie, particularly if accompanied by ruptured membranes, also alters the choice of uterine incision at cesarean delivery. A low transverse (Kerr) uterine incision has many surgical advantages and is generally the preferred approach for cesarean delivery for an abnormal lie (see Chapter 19 ). Because up to 25% of transverse incisions may require vertical extension for delivery of an infant from an abnormal lie, and the lower uterine segment is often poorly developed and insufficiently broad such that a traumatic delivery of the presenting part is made more difficult, other uterine incisions may be considered. A “J” or “T” extension of the low transverse incision results in a uterine scar that is more susceptible to subsequent rupture due to poor vascularization. Therefore in the uncommon case of a transverse or oblique lie with a poorly developed lower uterine segment, when a transverse incision is deemed unfeasible or inadequate, a vertical incision (low vertical or classical) may be a reasonable alternative. Intraoperative cephalic version may allow the use of a low transverse incision, but ruptured membranes or oligohydramnios may make this difficult. Uterine relaxing agents such as inhalational anesthetics or intravenous (IV) nitroglycerin may improve success of these maneuvers if the difficulty is attributable to a contracted uterine fundus. Deflection Attitudes Attitude refers to the position of the fetal head in relation to the neck. The normal attitude of the fetal head during labor is one of full flexion with the fetal chin against the upper chest. Deflexed attitudes include various degrees of deflection or even extension of the fetal neck and head ( Fig. 17-5 ), leading to, for example, face or brow presentations. Spontaneous conversion to a more normal, flexed attitude or further extension of an intermediate deflection to a fully extended position commonly occurs as labor progresses owing to resistance exerted by the bony pelvis and soft tissues. Although safe vaginal delivery is possible in many cases, experience indicates that cesarean delivery may be the most appropriate alternative when arrest of progress is observed. FIG 17-5 The normal “attitude” ( top ) shows the fetal vertex flexed on the neck. Partial deflexion ( middle ) shows the fetal vertex intermediate between flexion and extension. Full deflexion ( lower ) shows the fetal vertex completely extended with the face presenting. Face Presentation A face presentation is characterized by a longitudinal lie and full extension of the fetal neck and head with the occiput against the upper back ( Fig. 17-6 ). The fetal chin (mentum) is chosen as the point of designation during vaginal examination. For example, a fetus presenting by the face whose chin is in the right posterior quadrant of the maternal pelvis would be called a right mentum posterior ( Fig. 17-7 ). The reported incidence of face presentation ranges from 0.14% to 0.54% and averages about 0.2%, or 1 in 500 live births overall. The reported perinatal mortality rate, corrected for nonviable malformations and extreme prematurity, varies from 0.6% to 5% and averages about 2% to 3%. FIG 17-6 This fetus with the vertex completely extended on the neck enters the maternal pelvis in a face presentation. The cephalic prominence would be palpable on the same side of the maternal abdomen as the fetal spine. FIG 17-7 The point of designation from digital examination in the case of a face presentation is the fetal chin relative to the maternal pelvis. Left, right mentum posterior (RMP); middle, mentum anterior (MA); right, left mentum transverse (LMT). All clinical factors known to increase the general rate of malpresentation have been implicated in face presentation; many infants with a face presentation have malformations. Anencephaly, for instance, is found in about one third of cases of face presentation. Fetal goiter and tumors of the soft tissues of the head and neck may also cause deflexion of the head. Frequently observed maternal factors include a contracted pelvis or cephalopelvic disproportion in 10% to 40% of cases. In a review of face presentation, Duff found that one of these etiologic factors was found in up to 90% of cases. Early recognition of the face presentation is important, and the diagnosis can be suspected when abdominal palpation finds the fetal cephalic prominence on the same side of the maternal abdomen as the fetal back ( Fig. 17-8 ); however, face presen­tation is more often discovered by vaginal examination. In practice, fewer than 1 in 20 infants with face presentation is diagnosed by abdominal examination. In fact, only half of these infants are found by any means to have a face presentation before the second stage of labor, and half of the remaining cases are undiagnosed until delivery. However, perinatal mortality may be higher with late diagnosis. FIG 17-8 Palpation of the maternal abdomen in the case of a face presentation should find the fetal cephalic prominence on the side away from the fetal small parts, instead of on the same side, as in the case of a normally flexed fetal neck and head. Mechanism of Labor Knowledge of the early mechanism of labor for face presentation is incomplete. Many infants with a face presentation probably begin labor in the less extended brow position. With descent into the pelvis, the forces of labor press the fetus against maternal tissues; subsequent flexion (to a vertex presentation) or full extension of the head on the spine (to a face presentation) then occurs. The labor of a face presentation must include engagement, descent, internal rotation generally to a mentum anterior position, and delivery by flexion as the chin passes under the symphysis ( Fig. 17-9 ). However, flexion of the occiput may not always occur, and delivery in the fully extended attitude may be common. FIG 17-9 Engagement, descent, and internal rotation remain cardinal elements of vaginal delivery in the case of a face presentation, but successful vaginal delivery of a term-size fetus presenting a face generally requires delivery by flexion under the symphysis from a mentum anterior position, as illustrated here. The prognosis for labor with a face presentation depends on the orientation of the fetal chin. At diagnosis, 60% to 80% of infants with a face presentation are mentum anterior, 10% to 12% are mentum transverse, and 20% to 25% are mentum posterior. Almost all average-sized infants presenting mentum anterior with adequate maternal pelvic dimensions will achieve spontaneous or assisted vaginal delivery. Furthermore, most mentum transverse infants will rotate to the mentum anterior position and will deliver vaginally, and even 25% to 33% of mentum posterior infants will rotate and deliver vaginally in the mentum anterior position. In a review of 51 cases of persistent face presentation, Schwartz and colleagues found that the mean birthweight of those infants in a mentum posterior position who did rotate and deliver vaginally was 3425 g, compared with 3792 g for those infants who did not rotate and deliver vaginally. Persistence of the mentum posterior position with an infant of normal size, however, makes safe vaginal delivery less likely. Overall, 70% to 80% of infants with a face presenting can be delivered vaginally, either spontaneously or by low forceps in the hands of a skilled operator, whereas 12% to 30% require cesarean delivery. Manual attempts to convert the face to a flexed attitude or to rotate a posterior position to a more favorable mentum anterior position are rarely successful and increase both maternal and fetal risks. Again, IPV and breech extraction for face presentation historically are associated with unacceptably high fetal loss rates. Maternal deaths from uterine rupture and trauma have also been documented. Thus contemporary management through spontaneous delivery and cesarean delivery for other obstetric indications as necessary are the preferred routes for both maternal and fetal safety. Prolonged labor is a common feature of face presentation and has been associated with an increased number of intrapartum deaths; therefore prompt attention to an arrested labor pattern is recommended. In the case of an average or small fetus, an adequate pelvis, and hypotonic labor, oxytocin may be considered. No absolute contraindication to oxytocin augmentation of hypotonic labor in face presentations exists, but an arrest of progress despite adequate labor should call for cesarean delivery. Worsening of the fetal condition in labor is common. Salzmann and colleagues observed a tenfold increase in fetal compromise with face presentation. Several other observers have also found that abnormal fetal heart rate (FHR) patterns occur more often with face presentation. Continuous intrapartum electronic FHR monitoring of a fetus with face presentation is considered mandatory, but extreme care must be exercised in the placement of an electrode because ocular or cosmetic damage is possible. If external Doppler heart rate monitoring is inadequate and an internal electrode is recommended, placement of the electrode on the fetal chin is often preferred. Contraindications to vaginal delivery of a face presentation include macrosomia, nonreassurance of FHR monitoring even without arrested or protracted labor, or an inadequate maternal pelvis; cesarean delivery has been reported in as many as 60% of cases of face presentation for these reasons. If cesarean delivery is warranted, care should be taken to flex the head gently, both to accomplish elevation of the head through the hysterotomy incision as well as to avoid potential cervical nerve damage to the neonate. Forced flexion may also result in fetal injury, especially with fetal goiter or neck tumors. Fetal laryngeal and tracheal edema that results from the pressure of the birth process might require immediate nasotracheal intubation. Nuchal tumors or simple goiters, fetal anomalies that might have caused the malpresentation, require expert neonatal management, including the possibility of an ex utero intrapartum treatment (EXIT) procedure, which establishes a fetal/neonatal airway before the umbilical cord is clamped. Identification of and planning for these particular circumstances in the prelabor setting are ideal. Brow Presentation A fetus in a brow presentation occupies a longitudinal axis with a partially deflexed cephalic attitude midway between full flexion and full extension ( Fig. 17-10 ). The frontal bones are the point of designation. If the anterior fontanel is on the mother’s left side, with the sagittal suture in the transverse pelvic axis, the fetus would be in a left frontum transverse position ( Fig. 17-11 ). The reported incidence of brow presentation varies widely, from 1 in 670 to 1 in 3433, averaging about 1 in 1500 deliveries. Brow presentation is detected more often in early labor before flexion occurs to a normal attitude. Less frequently, further extension results in a face presentation. FIG 17-10 This fetus is in a brow presentation in a frontum anterior position. The head is in an intermediate deflexion attitude. FIG 17-11 In brow presentation, the anterior fontanel (frontum) relative to the maternal pelvis is the point of designation. Left, fetus in left frontum transverse (LFT); middle, frontum anterior (FA); right, left frontum anterior (LFA). In 1976, the perinatal mortality rate corrected for lethal anomalies and very low birthweight varied from 1% to 8%. In a study of 88,988 deliveries, corrected perinatal mortality rates for brow presentations depended on the mode of delivery; a loss rate of 16%, the highest in this study, was associated with manipulative vaginal birth. In general, factors that delay engagement are associated with persistent brow presentation. Cephalopelvic disproportion, prematurity, and high parity are often found and have been implicated in more than 60% of cases of persistent brow presentation. Detection of a brow presentation by abdominal palpation is unusual in practice. More often, a brow presentation is detected on vaginal examination. As in the case of a face presentation, diagnosis in labor is more likely. Fewer than 50% of brow presentations are detected before the second stage of labor, and most of the remainder are undiagnosed until delivery. Frontum anterior is reportedly the most common position at diagnosis, occurring about twice as often as either transverse or posterior positions. Although the initial position at diagnosis may be of limited prognostic value, the cesarean delivery rate is higher with frontum transverse or frontum posterior than with frontum anterior positioning. A persistent brow presentation requires engagement and descent of the largest (mento-occipital) diameter of the fetal head. This process is possible only with a large pelvis or a small infant, or both. However, most brow presentations convert spontaneously by flexion or further extension to either a vertex or a face presentation and are then managed accordingly. The earlier the diagnosis is made, the more likely conversion will occur spontaneously. Fewer than half of fetuses with persistent brow presentations undergo spontaneous vaginal delivery, but in most cases, a trial of labor is not contraindicated. Prolonged labors have been observed in 33% to 50% of brow presentations, and secondary arrest is not uncommon. Forced conversion of the brow to a more favorable position with forceps is contraindicated, as are attempts at manual conversion. One unexpected cause of persistent brow presentation may be an open fetal mouth pressed against the vaginal wall, splinting the head and preventing either flexion or extension ( Fig. 17-12 ). Although this is rare in phenotypically normal fetuses, it needs to be considered in anomalous conditions of the fetus such as epignathus, a rare oropharyngeal teratoma. FIG 17-12 The open fetal mouth against the vaginal sidewall may brace the head in the intermediate deflexion attitude as shown here. Similar to face presentations, minimal manipulation yields the best results if the FHR pattern remains reassuring. Expectant management may be justified, preferably with a relatively large pelvis in relation to fetal size and adequate labor progress, according to one large study. If a brow presentation persists with a large baby, successful vaginal delivery is unlikely, and cesarean delivery may be most prudent. Radiographic or computed tomographic (CT) pelvimetry is not used clinically, and one report states that although 91% of cases with adequate pelvimetry converted to a vertex or a face presentation and delivered vaginally, 20% with some form of pelvic contracture did also. Therefore regardless of pelvic dimensions, consideration of a trial of labor with careful monitoring of maternal and fetal condition may be appropriate. As in the case of a face presentation, oxytocin may be used cautiously to correct hypotonic contractions, but prompt resumption of progress toward delivery should follow. Compound Presentation Whenever an extremity, most commonly an upper extremity, is found prolapsed beside the main presenting fetal part, the situation is referred to as a compound presentation ( Fig. 17-13 ). The reported incidence ranges from 1 in 377 to 1 in 1213 deliveries. The combination of an upper extremity and the vertex is the most common. FIG 17-13 The compound presentation of an upper extremity and the vertex illustrated here most often spontaneously resolves with further labor and descent. This diagnosis should be suspected with any arrest of labor in the active phase or failure to engage during active labor. Diagnosis is made on vaginal examination by discovery of an irregular mobile tissue mass adjacent to the larger presenting part. Recognition late in labor is common, and as many as 50% of persisting compound presentations are not detected until the second stage. Delay in diagnosis may not be detrimental because it is likely that only the persistent cases require intervention. Although maternal age, race, parity, and pelvic size have been associated with compound presentation, prematurity is the most consistent clinical finding. The very small premature fetus is at great risk of persistent compound presentation. In late pregnancy, ECV of a fetus in breech position increases the risk of a compound presentation. Older, uncontrolled studies report elevated perinatal mortality rates with a compound presentation, with an overall rate of 93 per 1000. Higher loss rates of 17% to 19% have been reported when the foot prolapses. As with other malpresentations, fetal risk is directly related to the method of management. A fetal mortality rate of 4.8% has been noted if no intervention is required compared with 14.4% with intervention other than cesarean delivery. A 30% fetal mortality rate has been observed with IPV and breech extraction. These figures may demonstrate selection bias because it is possible that more often, the difficult cases were chosen for manipulative intervention. When intervention is necessary, cesarean delivery appears to be the only safe choice. Fetal risk in compound presentation is specifically associated with birth trauma and cord prolapse. Cord prolapse occurs in 11% to 20% of cases, and it is the most frequent complication of this malpresentation. Cord prolapse probably occurs because the compound extremity splints the larger presenting part and results in an irregular fetal aggregate that incompletely fills the pelvic inlet. In addition to the hypoxic risk of cord prolapse, common fetal morbidity includes neurologic and musculoskeletal damage to the involved extremity. Maternal risks include soft tissue damage and obstetric laceration. Again, although laboring is not proscribed, the prolapsed extremity should not be manipulated. However, it may spontaneously retract as the major presenting part descends. Seventy-five percent of vertex/upper extremity combinations deliver spontaneously. Occult or obscured cord prolapse is possible, and therefore continuous electronic FHR monitoring is recommended. The primary indications for surgical intervention (i.e., cesarean delivery) are cord prolapse, nonreassuring FHR patterns, and arrest of labor. Cesarean delivery is the only appropriate clinical intervention for cord prolapse and nonreassuring FHR patterns because both version extraction and repositioning the prolapsed extremity are associated with adverse outcome and should be avoided. From 2% to 25% of compound presentations require cesarean delivery. Protraction of the second stage of labor and dysfunctional labor patterns have been noted to occur more frequently with persistent compound presentations. As in other malpresentations, spontaneous resolution occurs more often, and surgical intervention is less frequently necessary in those cases diagnosed early in labor. Small or premature fetuses are more likely to have persistent compound presentations but are also more likely to have a successful vaginal delivery. Persistent compound presentation with parts other than the vertex and hand in combination in a term-sized infant has a poor prognosis for safe vaginal delivery, and cesarean delivery is usually necessary. However, a simple compound presentation (e.g., hand) may be allowed to labor, if labor is progressing normally with reassuring fetal status. Breech Presentation The infant presenting as a breech occupies a longitudinal axis with the cephalic pole in the uterine fundus. This presentation occurs in 3% to 4% of labors overall, although it is found in 7% of pregnancies at 32 weeks and in 25% of pregnancies of less than 28 weeks’ duration. The three types of breech are noted in Table 17-1 . The infant in the frank breech position is flexed at the hips with extended knees (pike position). The complete breech is flexed at both joints (tuck position), and the footling or incomplete breech has one or both hips partially or fully extended ( Fig. 17-14 ). TABLE 17-1 BREECH CATEGORIES TYPE OVERALL % OF BREECHES RISK OF PROLAPSE (%) † PREMATURE (%) ‡ Frank 48-73 * † ‡ 0.5 38 Complete 4.6-11.5 † ‡ 4-6 12 Footling 12-38 ‡ 15-18 50   * Data from Collea JV, Chein C, Quilligan EJ. The randomized management of term frank breech presentation: a study of 208 cases. Am J Obstet Gynecol. 1980;137:235-244. † Data from Gimovsky ML, Wallace RL, Schifrin BS, Paul RH. Randomized management of the nonfrank breech presentation at term: a preliminary report. Am J Obstet Gynecol. 1983;146:34-40. ‡ Data from Brown L, Karrison T, Cibils LA. Mode of delivery and perinatal results in breech presentation. Am J Obstet Gynecol. 1994;171:28-34. FIG 17-14 The complete breech is flexed at the hips and flexed at the knees. The incomplete breech shows incomplete deflexion of one or both knees or hips. The frank breech is flexed at the hips and extended at the knees. The diagnosis of breech presentation may be made by abdominal palpation or vaginal examination and confirmed by ultrasound. Prematurity, fetal malformation, müllerian anomalies, and polar placentation are commonly observed causative factors. High rates of breech presentation are noted in certain fetal genetic disorders, including trisomies 13, 18, and 21; Potter syndrome; and myotonic dystrophy. Conditions that alter fetal muscular tone and mobility—such as increased and decreased amniotic fluid, for example—also increase the frequency of breech presentation. The breech head appears dolichocephalic on ultrasound, and for that reason, the biparietal diameter (BPD) appears small. However, the head circumference remains unaffected. This difference may be as much as 16+ days (95% confidence interval [CI], 14.3 to 18.1; P = .001). Whereas the contracted BPD may affect ultrasound-determined weight estimates of the fetus, an occipitofrontal diameter (OFD) to BPD ratio of greater than 1.3 in the absence of other indicators of growth delay signals the deformation characteristic of the breech-presenting fetus. Approximately 80% of breech fetuses will have a dolichocephalic contour, previously termed the “breech head.” The fundus of the uterus assumes a more elongated contour than the bowl-like developed lower uterine segment. Thus it is believed that forces external to the fetus are responsible for this head shape. Because both dolichocephaly and breech may be associated with a genetically and phenotypically anomalous fetus, it behooves the sonologist to perform a detailed survey of the fetal anatomy prior to assuming the presence of the “breech head.” Mechanism and Conduct of Labor and Vaginal Delivery The two most important elements for the safe conduct of vaginal breech delivery are continuous electronic FHR monitoring and noninterference until spontaneous delivery of the breech to the umbilicus has occurred. Early in labor, the capability for immediate cesarean delivery should be established. Anesthesia should be available, the operating room readied, and appropriate informed consent obtained (discussed later). Two obstetricians should be in attendance in addition to a pediatric team. Appropriate training and experience with vaginal breech delivery are fundamental to success. Although experience is becoming infinitely less common, simulation of breech deliveries will help to maintain these skills. The instrument table should be prepared in the customary manner, with the addition of Piper forceps and extra towels. No contraindication exists to epidural analgesia in labor, and many believe epidural anesthesia to be an asset in the control and conduct of the second stage. The infant presenting in the frank breech position usually enters the pelvic inlet in one of the diagonal pelvic diameters ( Fig. 17-15 ). Engagement has occurred when the bitrochanteric diameter of the fetus has progressed beyond the plane of the pelvic inlet, although by vaginal examination, the presenting part may be palpated only at a station of −2 to −4 (out of 5). As the breech descends and encounters the levator ani muscular sling, internal rotation usually occurs to bring the bitrochanteric diameter into the anteroposterior (AP) axis of the pelvis. The point of designation in a breech labor is the fetal sacrum ; therefore when the bitrochanteric diameter is in the AP axis of the pelvis, the fetal sacrum will lie in the transverse pelvic diameter ( Fig. 17-16 ). FIG 17-15 The breech typically enters the inlet with the bitrochanteric diameter aligned with one of the diagonal diameters, with the sacrum as the point of designation in the other diagonal diameter. This illustrates a left sacrum posterior alignment. FIG 17-16 With labor and descent, the bitrochanteric diameter generally rotates toward the anteroposterior axis, and the sacrum rotates toward the transverse axis. If normal descent occurs, the breech will present at the outlet and will begin to emerge, first as sacrum transverse, then rotating to sacrum anterior. This direction of rotation may reflect the greater capacity of the hollow of the posterior pelvis to accept the fetal chest and small parts. Crowning occurs when the bitrochanteric diameter passes under the pubic symphysis. It is important to emphasize that operator intervention is not yet needed or helpful, other than possibly to perform the episiotomy if indicated and to encourage maternal expulsive efforts. Premature or aggressive intervention may adversely affect the delivery in at least two ways. First, complete cervical dilation must be sustained for sufficient duration to retard retraction of the cervix and entrapment of the aftercoming fetal head. Rushing the delivery of the trunk may result in cervical retraction. Second, the safe descent and delivery of the breech infant must be the result of uterine and maternal expulsive forces only in order to maintain neck flexion. Any traction by the provider in an effort to speed delivery would encourage deflexion of the neck and result in the presentation of the larger occipitofrontal fetal cranial profile to the pelvic inlet ( Fig. 17-17 ). Such an event could be catastrophic. Rushed delivery also increases the risk of a nuchal arm, with one or both arms trapped behind the head above the pelvic inlet. Entrapment of a nuchal arm makes safe vaginal delivery much more difficult because it dramatically increases the aggregate size of delivering fetal parts that must egress vaginally. Safe breech delivery of an average-sized infant, therefore, depends predominantly on maternal expulsive forces and patience, not traction, from the provider. FIG 17-17 The fetus emerges spontaneously (A), whereas uterine contractions maintain cephalic flexion. Premature aggressive traction (B) encourages deflexion of the fetal vertex and increases the risk of head entrapment or nuchal arm entrapment. As the frank breech emerges further, the fetal thighs are typically flexed firmly against the fetal abdomen, often splinting and protecting the umbilicus and cord. The Pinard maneuver may be needed to facilitate delivery of the legs in a frank breech presentation. After delivery to the umbilicus has occurred, pressure is applied to the medial aspect of the knee, which causes flexion and subsequent delivery of the lower leg. Simultaneous to this, the fetal pelvis is rotated away from that side ( Fig. 17-18 ). This results in external rotation of the thigh at the hip, flexion of the knee, and delivery of one leg at a time. The dual movement of counterclockwise rotation of the fetal pelvis as the operator externally rotates the right thigh and clockwise rotation of the fetal pelvis as the operator externally rotates the fetal left thigh is most effective in facilitating delivery. The fetal trunk is then wrapped with a towel to provide secure support of the body while further descent results from expulsive forces from the mother. The operator primarily facilitates the delivery of the fetus by providing support and guiding the body through the introitus. The operator is not applying outward traction on the fetus, which might result in deflexion of the fetal head or nuchal arm. FIG 17-18 After spontaneous expulsion to the umbilicus, external rotation of each thigh (A) combined with opposite rotation of the fetal pelvis results in flexion of the knee and delivery of each leg (B). When the scapulae appear at the introitus, the operator may slip a hand over the fetal shoulder from the back ( Fig. 17-19 ); follow the humerus; and, with movement from medial to lateral, sweep first one and then the other arm across the chest and out over the perineum. Gentle rotation of the fetal trunk counterclockwise assists delivery of the right arm, and clockwise rotation assists delivery of the left arm (turning the body “into” the arm). This accomplishes delivery of the arms by drawing them across the fetal chest in a fashion similar to that used for delivery of the legs ( Fig. 17-20 ). These movements cause the fetal elbow to emerge first, followed by the forearm and hand. Once both arms have been delivered, if the vertex has remained flexed on the neck, the chin and face will appear at the outlet, and the airway may be cleared and suctioned ( Fig. 17-21 ). FIG 17-19 When the scapulae appear under the symphysis, the operator reaches over the left shoulder, sweeps the arm across the chest (A), and delivers the arm (B). FIG 17-20 Gentle rotation of the shoulder girdle facilitates delivery of the right arm. FIG 17-21 Following delivery of the arms, the fetus is wrapped in a towel for control and is slightly elevated. The fetal face and airway may be visible over the perineum. Excessive elevation of the trunk is avoided. With further maternal expulsive forces alone, spontaneous controlled delivery of the fetal head often occurs. If not, delivery may be accomplished with a simple manual effort to maximize flexion of the vertex using pressure on the fetal maxilla (not the mandible), the Mauriceau-Smellie-Veit maneuver, using gentle downward traction along with suprapubic pressure (Credé maneuver; Fig. 17-22 ). Although maxillary pressure facilitates flexion, the main force effecting delivery remains the mother. FIG 17-22 Cephalic flexion is maintained by pressure ( black arrow ) on the fetal maxilla, not the mandible. Often, delivery of the head is easily accomplished with continued expulsive forces from above and gentle downward traction. Alternatively, the operator may apply Piper forceps to the aftercoming head. The application requires very slight elevation of the fetal trunk by the assistant, while the operator kneels and applies the Piper forceps from beneath the fetus directly to the fetal head in the pelvis. Delivery of the breech presenting fetus, therefore, should occur on a table/bed capable of allowing the operators to correctly position themselves for the application of forceps. Direct access to the perineum is required. If a delivery bed is used, merely dropping the foot of the bed will be inadequate. The position of the operator for applying the forceps is depicted in Figure 17-23 , which also demonstrates how excessive elevation by the assistant may potentially cause harm to the neonate. Hyperextension of the fetal neck from excessive elevation of the fetal trunk, shown in Figure 17-23 , should be avoided because of the potential for spinal cord injury. FIG 17-23 Demonstration of incorrect assistance during the application of Piper forceps. The assistant hyperextends the fetal neck, a position that increases the risk for neurologic injury. Piper forceps are characterized by absence of pelvic curvature. This modification allows direct application to the fetal head and avoids conflict with the fetal body that would occur with the application of standard instruments from below. The assistant maintains control of the fetal body while the forceps are inserted into the vagina from beneath the fetus by the primary operator. The blade to be placed on the maternal left is held by the handle in the operator’s left hand; the blade is inserted with the operator’s right hand in the vagina along the left maternal sidewall and is placed against the right fetal parietal bone. The handle of the right blade is then held in the operator’s right hand and is inserted by the left hand along the right maternal sidewall and placed against the left fetal parietal bone. At this point, the assistant allows the fetal body to rest on the shank and handles of the forceps. Gentle downward traction on the forceps with the fetal trunk supported on the forceps shanks results in controlled delivery of the vertex ( Fig. 17-24 ). Forceps application controls the fetal head and prevents extension of the head on the neck. Application of Piper forceps to the aftercoming head may be advisable both to ensure control of the delivery and to maintain optimal operator proficiency in anticipation of deliveries that may require their use. FIG 17-24 The fetus may be laid on the forceps and delivered with gentle downward traction, as illustrated here. Arrest of spontaneous progress in labor with adequate uterine contractions necessitates consideration of cesarean delivery. Any evidence of fetal compromise or sustained cord compression on the basis of continuous electronic FHR monitoring also requires consideration of cesarean delivery. Vaginal interventions directed at facilitating delivery of the breech complicated by an arrest of spontaneous progress are discouraged because fetal and maternal morbidity and mortality are both greatly increased. However, if labor is deemed to be hypotonic by internally monitored uterine pressures, oxytocin is not contraindicated. Mechanisms of descent and delivery of the incomplete and the complete breech are not unlike those used for the frank breech described earlier; at least one leg may not require attention. The risk of cord prolapse or entanglement is greater, and hence the possibility of emergency cesarean delivery is increased. Furthermore, incomplete and complete breeches may not be as effective as cervical dilators as either the vertex or the larger aggregate profile of the thighs and buttocks of the frank breech. Thus the risk of entrapment of the aftercoming head is increased, and as a result, primary cesarean delivery is often advocated for nonfrank breech presentations. However, the randomized trial of Gimovsky and colleagues found vaginal delivery of the nonfrank breech to be reasonably safe. Contemporary Management of the Term Breech Debate has largely diminished about the proper management of the term breech. Much of the older data were derived from relatively few studies of varied methodologies, patient populations, and multiple retrospective cohort analyses, which are subject to bias. These reports indicated that the perinatal mortality rate for the vaginally delivered breech appears to be greater than for its cephalic counterpart, but much of the reported perinatal mortality rate associated with breech presentation was largely due to lethal anomalies and complications of prematurity, both of which are found more frequently among breech infants. Excluding anomalies and extreme prematurity, the corrected perinatal mortality reported by some investigators approached zero regardless of the method of delivery, whereas others found that even with exclusion of these factors, the term breech infant has been found to be at higher risk for birth trauma and asphyxia. To date, only three randomized trials have been reported. Although conclusions regarding the safety of breech vaginal delivery from a fetal standpoint may continue to vary, the practical reality today is that intentional vaginal breech delivery is rare. A summary of some of the reported complications is listed in Table 17-2 . Overall, consideration of a potential breech vaginal delivery must be mutually agreed on by the patient and the physician after complete informed consent is obtained. TABLE 17-2

Share this:

  • Click to share on Twitter (Opens in new window)
  • Click to share on Facebook (Opens in new window)

Related posts:

  • Operative Vaginal Delivery
  • Placenta Accreta
  • Prolonged and Postterm Pregnancy
  • Mental Health and Behavioral Disorders in Pregnancy

the presenting diameter in brow presentation

Stay updated, free articles. Join our Telegram channel

Comments are closed for this page.

the presenting diameter in brow presentation

Full access? Get Clinical Tree

the presenting diameter in brow presentation

IMAGES

  1. Presenting diameter in different head attitudes ... (*) Bregma always

    the presenting diameter in brow presentation

  2. presenting part in brow presentation

    the presenting diameter in brow presentation

  3. Presenting diameters

    the presenting diameter in brow presentation

  4. Presenting diameters

    the presenting diameter in brow presentation

  5. Presenting diameters

    the presenting diameter in brow presentation

  6. Brow Presentation and Birth Injury

    the presenting diameter in brow presentation

VIDEO

  1. Brow presentation

  2. Fans of the Brow Trophy Presentation! # Stays in AZ!!

  3. 2baht 2014 Thailand Coin Review Rama IX-Coin Collecting Coin Values

  4. Brow Presentation X-ray

  5. Inch faster then measuring the diameter of your exhaust

  6. Presentation of fetus

COMMENTS

  1. Delivery, Face and Brow Presentation

    This is the presenting diameter in face presentation where the neck is hyperextended. ... Mechanism of Labor in Brow Presentation. As this presentation is considered unstable, it is usually converted into a face or an occiput presentation. Due to the cephalic diameter being wider than the maternal pelvis, the fetal head cannot engage; thus ...

  2. Face and Brow Presentation

    In the brow presentation, the occipitomental diameter, which is the largest diameter of the fetal head, is the presenting portion. Descent and internal rotation occur only with an adequate pelvis and if the face can fit under the pubic arch. While the head descends, it becomes wedged into the hollow of the sacrum.

  3. Presenting diameters

    Brow presentation Incidence: ranges from 1:1000 to 1:3500 Rarest malpresentation The presenting diameter 13.5cm ... Face presentation Incidence : 1:600- 1:1500 Due to hyper-extension of fetal head Presenting diameter 9.5 cm (submento-bregmatic diameter ) ...

  4. 7.10 Brow presentation

    7.10.1 Diagnosis. 7.10.2 Management. Foetus alive. Foetus dead. Brow presentation constitutes an absolute foeto-pelvic disproportion, and vaginal delivery is impossible (except with preterm birth or extremely low birth weight). This is an obstetric emergency, because labour is obstructed and there is a risk of uterine rupture and foetal distress.

  5. What Is Brow Presentation? What Are Its Complications?

    This is the ideal position that makes delivery easier as the baby's head will be in its smallest possible diameter in this presentation. This helps the baby to easily pass through the birth canal. However, not all presentations are as perfect as the head first presentation and brow presentation is one such complicated presentation of the baby.

  6. Face and brow presentations in labor

    The vast majority of fetuses at term are in cephalic presentation. Approximately 5 percent of these fetuses are in a cephalic malpresentation, such as occiput posterior or transverse, face ( figure 1A-B ), or brow ( figure 2) [ 1 ]. Diagnosis and management of face and brow presentations will be reviewed here.

  7. Presentation and Mechanisms of Labor

    Approximately two thirds of brow presentations will convert to vertex or face. 2 Fortunately, this is a rare presentation, ... Even if vaginal delivery of a mentum anterior presentation is attempted, the diameter of the presenting part may exceed the maternal pelvic capacity. A situation like this also would require an abdominal delivery.

  8. PDF Face, brow and shoulder presentations

    for face presentations. The positive diagnosis of brow presentation is normally made in labour when on vaginal examination the supraorbi­ tal ridges and anterior fontanelle are felt. The skull diameter attempt­ ing to engage is the mento-vertical, which is that extending from the point of the chin to the furthest point on the vault of the ...

  9. Brow Presentation

    Presentation: This term denotes the portion of the fetus lying in relation to the maternal pelvic brim. On vaginal examination, the presenting part of the fetus can be palpated through cervix. The presentations can be vertex, brow, face, breech, arm, shoulder, compound, or cord. All presentations other than the vertex are considered as ...

  10. Management of malposition and malpresentation in labour

    Brow: brow presentation represents deflexion of the fetal head but not to the same degree as the complete extension causing a face presentation, with an incidence of approximately 1 in 2000 births. In a brow presentation, the presenting diameter is mento-vertical, at approximately 13 cm, and is therefore the most unfavourable of cephalic ...

  11. Mechanism and management of normal labour

    The presenting diameter in a brow is the mentovertical (13.5 cm), which exceeds all pelvic diameters in a normal pelvis. There is no mechanism of labour in a brow presentation. Occasionally, a brow will flex during early labour and may proceed as an OP.

  12. Malpositions and malpresentations of the fetal head

    The mentum (chin) is the denominator and the presenting diameter is submentobregmatic (9.5 cm). Most face presentations are chin anterior (mentoanterior) in the maternal pelvis and in such cases spontaneous/assisted vaginal delivery can occur with the fetal head being born by flexion of the neck in 60-90% cases.

  13. Malpresentation, Malposition, Cephalopelvic Disproportion and Obstetric

    Brow presentation. Brow presentation occurs in 1 in 1500-3000 deliveries. The head is partially deflexed (extended), with the largest diameter of the head presenting (mento‐vertical, 13.5 cm). The forehead is the lowest presenting part but diagnosis relies on identifying the prominent orbital ridges lying laterally.

  14. Malpresentations and malpositions

    Brow presentation. This occurs in only approximately 1:700 and 1:1500 births and is the least favourable for delivery (Fig. 45.4). The presenting diameter is mentovertical, measuring 14 cm. The supraorbital ridges and the bridge of the nose will be palpable on vaginal examination.

  15. Delivery, Face And Brow Presentation

    Face and brow presentation is a malpresentation during labor when the presenting part is either the face or, in the case of brow presentation, it is the area between the orbital ridge and the anterior fontanelle. ... This is the presenting diameter in vertex presentation. Suboccipito-frontal: from the anterior part of bregma to the occipital ...

  16. Face and brow presentations in labor

    Patients with a clinically adequate or proven pelvis can undergo a trial of labor since many brow presentations are transitional. In one review, when brow presentation was diagnosed early in labor, 67 to 75 percent of fetuses spontaneously converted to a more favorable presentation and delivered vaginally.

  17. Face and Brow Presentation: Overview, Background, Mechanism of Labor

    Nonvertex presentations (including breech, transverse lie, face, brow, and compound presentations) occur in less than 4% of fetuses at term. Malpresentation of the vertex presentation occurs if there is deflexion or extension of the fetal head leading to brow or face presentation, respectively.

  18. Delivery, Face and Brow Presentation

    Point of Care - Clinical decision support for Delivery, Face and Brow Presentation. Treatment and management. Introduction, Anatomy and Physiology, Indications, Contraindications, Equipment, Personnel, Preparation, Technique or Treatment, Complications, Clinical Significance, Enhancing Healthcare Team Outcomes

  19. Malpositions and malpresentations of the fetal head

    Brow presentation. The incidence of brow is between 1 in 700 and 1 in 1500 deliveries. ... In brow presentations, the head is deflexed and presents to the pelvis with the largest anteroposterior diameter. Many brow presentations in early labour are transient proceeding to complete extension (face) or flexion (vertex) as labour progresses. ...

  20. Face Presentation

    A type of cephalic presentation in which the presenting part is the face, the area between chin and glabella. The incidence varies from 1 in 500 to 1 in 1000 deliveries. Primary face presentation is rare. Secondary face presentation caused by extension of head during labor is common. Thus, the diagnosis is usually made during active phase of ...

  21. Delivery, Face and Brow Presentation

    Abstract. The term presentation describes the leading part of the fetus or the anatomical structure closest to the maternal pelvic inlet during labor. The presentation can roughly be divided into the following classifications: cephalic, breech, shoulder, and compound. Cephalic presentation is the most common and can be further subclassified as ...

  22. Physiology and Management of Abnormal Labour. Notes on Face

    Flexion often occurs suddenly. 3.6 Similarities between Face and Brow presentations Face and brow presentation increase the risk of difficult labor, with vaginal delivery being possible only for mentum anterior face positions due to maximum extension of the fetal neck when in the posterior position.

  23. Malpresentations

    The reported incidence of face presentation ranges from 0.14% to 0.54% and averages about 0.2%, or 1 in 500 live births overall. The reported perinatal mortality rate, corrected for nonviable malformations and extreme prematurity, varies from 0.6% to 5% and averages about 2% to 3%. FIG 17-6.