Overview of Delivery, Face and Brow Presentation
“Presentation” refers to which part of the baby in the mother’s womb is nearest to the pelvis or birth canal during labor. The four main types are cephalic (head first), breech (feet or buttocks first), shoulder, and compound (where another part of the body presents along with the head or buttocks). Among these, cephalic presentation is most frequent. It can take on several forms, including vertex (when the baby’s neck is bent onto the chin, lessening the head size), sinciput, brow, face, and chin.
The vertex presentation is most widespread during full-term labor. A less common type is face presentation, where the baby’s chin leads the way because the neck is extended backward, not forwards. This causes the baby’s back of the head to touch its own back. Face malpresentation is uncommon, found in roughly 1 in every 600 deliveries.
Brow presentation is when the neck is not extended as much as in face presentation. In this case, the area between the baby’s soft spot (anterior fontanelle) and the brows is the part that presents first. It’s the least common malpresentation, happening only in about 1 to 4000 deliveries.
Both face and brow presentations are a result of the baby’s neck extending back instead of bending forward. Various conditions and risk factors can lead to this. Some maternal risk factors include delivering the baby prematurely, having a narrow or flat pelvis, having multiple children, or having previously delivered via cesarean section. For babies, factors include a rare brain condition (anencephaly), the umbilical cord wrapping around the neck multiple times, growths in the neck area, being significantly heavier or bigger (macrosomia), and having too much fluid in the womb (polyhydramnios). Furthermore, Black mothers tend to experience face and brow presentations more frequently than other ethnic groups.
These types of malpresentation usually are diagnosed in the later stage of labor by physical examination. In the case of face presentation, a doctor can feel the baby’s facial features and chin. Depending on where the chin is, face presentation is grouped into types: mentum anterior (chin facing forward), posterior (chin facing backwards), or transverse (chin facing sideways). For brow presentation, a doctor can feel the baby’s fontanelle and face, but not the mouth or chin. Similarly, the location of the fontanelle is used to describe it as frontal anterior, posterior, or again, transverse.
Identifying the exact presentation can be a bit tricky, especially as face presentation can be mistaken for breech presentation. An ultrasound can be done to verify the correct presentation. In this examination, the angle between the baby’s back of the head and spine can be measured, or it can show that the chin is not resting on the chest. However, an ultrasound does not significantly predict the labor’s outcome.
Anatomy and Physiology of Delivery, Face and Brow Presentation
Before we talk about how babies are born in different positions, it’s important to understand some parts of a woman’s body and their measurements.
The pelvis has three main areas: the top part (pelvic inlet), the middle (mid-pelvis), and the bottom (pelvic outlet). The pelvic inlet has four types of lengths: front-to-back, side-to-side, and two diagonal measurements. There are three key front-to-back measurements, which are known as the conjugates. The most important one, called the obstetrical conjugate, is about 10.5 cm. It is the distance from the back part of the pelvis (sacral promontory) to 1 cm below the top part of the pubic bone (symphysis pubis). This is important during childbirth as the baby’s head needs to pass through this area. The side-to-side measurement is about 13.5 cm, which is the widest point. The narrowest part of the mid-pelvis is about 10 cm.
If we measure the baby’s head in different ways, we find six measurements. The shortest is 9.5 cm, which is from the back of the baby’s head (occipital protuberance) to the soft spot on the top of their head (bregma). The longest measurement is 13.5 cm, from the soft spot on top of their head to their chin.
In a normal childbirth, the baby moves in a certain way to fit through the mother’s pelvis. These moves are called the cardinal movements. They start with the baby’s head entering the pelvis (engagement), moving downwards (descent), bending the neck (flexion), turning the head (internal rotation), extending the neck to get the head out (extension), turning the head back to its original position (external rotation) and finally, pushing out the shoulders (expulsion). These steps happen naturally except in certain rare positions.
For some childbirth positions such as the face and brow presentation, it’s impossible for the baby to move in these ways. For instance, in a brow presentation, the baby’s head is actually wider than the narrowest part of the mother’s pelvis, which means the baby can’t be born naturally. However, if the baby manages to change to a different position, natural birth may be possible. In a face presentation, vaginal birth can still occur and the techniques in this particular situation will be explained in detail later.
Why do People Need Delivery, Face and Brow Presentation
If a baby is facing upwards, or ‘face presentation’ during birth, it’s still possible for a natural delivery through the birth canal. But this should be a decision made based on the mother’s preference. It’s crucial for doctors to have clear conversations with expecting mothers, outlining the risks and benefits of a natural birth versus a cesarean section, which is surgery to deliver the baby. The goal is always to make sure that mothers and their families are informed, and that the birth is safe and successful.
When a Person Should Avoid Delivery, Face and Brow Presentation
In certain circumstances, natural childbirth can be risky if the baby’s face is oriented in a particular way in the womb. This situation, called “face presentation,” is not suited for a natural birth if the baby’s chin (the “mentum”) is facing the mother’s back (described as “posterior”) or lying sideways (“transverse”). In these positions, the baby’s forehead may be pressing against the mother’s pelvic bone, and the baby’s short neck, already fully extended, can’t bridge the curve of the mother’s lower back bone (the “sacrum”).
Additionally, in this posture, the size of the baby’s head is larger than the space in the mother’s pelvis, preventing the baby from moving down the birth canal. For these reasons, doctors recommend a c-section, or cesarean delivery. It’s very risky to try to manually turn the baby from a face presentation to a head-first one, or try to use aids like forceps to rotate the baby’s position.
The other situation when a natural birth isn’t suggested is if the baby’s forehead, or the “brow,” maintains its presentation. The only exception to this rule is when the baby is noticeably smaller than normal, or the mother has a larger than usual pelvic size.
Equipment used for Delivery, Face and Brow Presentation
It’s recommended that an unborn baby’s heart rate is monitored continuously when the baby is in face or brow position in the womb. This is because unusual heart rhythms are often seen in these situations. One piece of research discovered that only in 14% of cases where the baby was facing upwards, there were no unusual patterns in the heart rate readings.
The use of external monitoring tools is suggested to avoid harming the baby’s eyes. If there’s a need for internal monitoring, it should be done very carefully by placing the monitoring devices on the hard parts of the baby’s body.
Who is needed to perform Delivery, Face and Brow Presentation?
When a baby is about to be born in a difficult position, such as with their face or forehead first, it’s important to have a special team of doctors and nurses ready. This can often include:
1. A maternal team: This group is there to support the mother during labor. It may include midwives, who have special training in helping mothers during childbirth, obstetricians, who are doctors specializing in pregnancy and child birth, and labor nurses, who provide care to mothers during childbirth.
2. A neonatal team: These are health care professionals who take care of the newborn baby right after birth. For example, they’ll be there in case the baby needs help breathing right after birth (which is sometimes referred to as ‘resuscitation’).
3. An anesthesiology team: These are doctors and nurses who help to control the mother’s pain during labor and birth. For example, they may give an epidural, which is a special kind of pain medication that’s used during childbirth.
4. An operating room team: This team would be needed if the baby can’t be delivered naturally and a cesarean section (or ‘C-section’, which is surgery to deliver the baby) is needed urgently.
This team of different professionals ensures the safety of the mother and the newborn during a complicated birth.
Preparing for Delivery, Face and Brow Presentation
If a baby is positioned with their face or brow first for birth (instead of the top of their head), there’s no special preparation needed. However, it’s crucial for doctors and nurses to talk with the mother and her birth partner about the options for labor and delivery. It’s important to get their agreement on the chosen plan before moving forward.
Besides, medical teams involved in the birth, such as newborn care specialists, anesthesiology (pain management) experts, and operating room staff, should be informed and made ready. This way, everyone can coordinate their efforts to ensure the safest possible birth for both mother and baby.
How is Delivery, Face and Brow Presentation performed
Understanding Baby’s Position During Childbirth: Face and Brow Presentation
Often, during childbirth, the baby descends in the womb due to the pressure exerted by the uterus and the fluid surrounding the baby. In some cases, the baby’s neck tilts back instead of forward as it descends. The baby’s internal rotation, or which way they turn inside the womb, influences the way they will be delivered. If the baby’s chin rotates towards the mother’s spine, delivery through the birth canal would not be possible and a cesarean section – also known as C-section – is required. It varies from case to case; some mothers with previous childbirth experience or a smaller baby size might watch and wait for the baby to rotate their chin towards the birth canal before delivering. Usually, first-time mothers or mothers with larger babies are more likely to need a C-section.
When the baby’s chin is rotated towards the mother’s pubic bone, it’s termed as mentum-anterior. In such cases, the baby continues to descend through the birth canal, and about 73% of them are delivered naturally. During this, the baby’s chin pushes against the mother’s pubic bone and the head is born through flexion. Following this, the shoulders are delivered in the same way as a vertex (head-first) delivery.
Now, let’s discuss the brow presentation, where the baby’s forehead is first to come out during childbirth. This presentation is usually unstable as it spontaneously converts into a face-first or top-of-the-head-first presentation. Because the baby’s head is wider than the mother’s pelvis in these cases, the baby’s head can’t engage, or enter, the birth canal. So, the brow presentation can lead to a difficult natural delivery. Unless the baby is small or the mother’s pelvis is very wide, a C-section is usually necessary for a safe delivery.
Possible Complications of Delivery, Face and Brow Presentation
As the use of cesarean section (C-section) becomes more common for infants in awkward positions, the likelihood of harmful outcomes for mothers and newborns during a face presentation (when the baby’s face is pointed towards the birth canal) has greatly decreased. However, complications can still occur due to the unique challenges of this position during labor.
The baby’s position can make it harder for their head to move down the birth canal, which can make labor last longer. Extended labor can cause stress for the baby, leading to abnormal heart rhythms. If labor stops or the baby shows signs of distress, which can be seen on a monitor that tracks their heart rate during labor (cardiotocography), an emergency C-section might be necessary. A C-section can also have complications during and after the operation. Moreover, due to the baby’s position and the potentially long labor duration in a face presentation, newborns can have considerable swelling of the skull and face. This swelling may affect the baby’s airway, leading to difficulties breathing after birth and possibly requiring a breathing tube.
All these factors contribute to higher rates of C-sections and admissions to neonatal intensive care units for babies in face or brow presentations, compared to cephalic presentations (when the baby’s head is pointing towards the birth canal). Also, newborns with face presentations have higher composite scores, which are used to evaluate a baby’s overall health at birth.
What Else Should I Know About Delivery, Face and Brow Presentation?
During a normal childbirth (known as vertex presentation), the baby’s head bends forward, bringing the chin to the chest. This position forms the smallest possible head size of around 9.5 cm. However, in some cases, the baby’s neck bends backwards (in face and brow presentation), resulting in larger head sizes. As a result, the baby’s head enters the birth canal later and labor takes longer. It also increases the risk of labor not progressing as expected compared to a normal childbirth.
Furthermore, if the baby’s chin is positioned at the back, it becomes impossible for the baby’s neck to bend further. This is because the baby’s brows are pressing against the symphysis pubis, a joint at the front of the pelvis. In this situation, it is impossible for the baby to travel through the birth canal naturally. This type of birth is considered impossible to deliver naturally and requires an emergency C-section (surgical procedure to deliver the baby). Any manual attempts to change the baby’s position or use tools to rotate it to a more favourable position are considered dangerous and are usually not done.
