Why Is The Fetal Position Important?
The fetal position can determine the ease or difficulty of your childbirth. Your infant may assume one of various possible baby birth positions by the end of the gestation period, which is also a deciding factor for a vaginal birth or cesarean delivery. If your baby has shifted to a head-first position by the end of the term, they can descend through your vaginal opening without difficulty during delivery. However, if your baby doesn’t move to a feasible position, your OB/GYN may decide on an alternative delivery method. This post discusses the various fetal positions your baby may present in when you’re in labor and its impact on the delivery process.
Different Fetal Positions During Pregnancy
Before the due date, your baby will drop down into the pelvis. Here are the different positions your baby can get into when you are preparing for your delivery.
1. Occiput anterior (OA)
This is the ideal position your baby could attain towards delivery. The baby moves into the pelvis with her head-down, facing the mother’s back with chin tucked to the chest. Her head points towards the birthing canal. This is called the longitudinal lie. Termed the vertex presentation of the fetus, this position is generally attained between 32nd and 36th weeks of gestation (1). The baby will stay in the same position for the rest of your pregnancy. This position is considered ideal for the baby to come out of the birthing canal with head first. There are two more presentations in the OA position: i. Face and brow presentation: (2) The baby will remain in the OA position, but her face and not head will be pointing towards the birth canal. This happens when her chin is pointing outward instead of being tucked against the chest. The doctor can identify this position during a vaginal examination, by feeling the bony jaws and the mouth of the baby. In brow presentation, the baby will be in the OA position but her forehead will be pointing towards the birth canal. During the vaginal examination, the doctor can feel the anterior fontanelle and the orbits of the forehead (2) ii. Compound presentation: The baby is positioned anteriorly with one of her arms lying along her head pointing towards the birthing canal. The arms may slide back during the delivering process, but when they don’t, then extra care needs to be taken while taking out the baby safely.
2. Occiput posterior (OP)
The baby moves into the pelvis with her head-down but facing the front/abdomen of the mother. This position is also known as ‘sunny-side up’ or ‘face up’ position. OA and OP are called the cephalic or head-first positions. Generally, around 10-34% of babies remain in OP position during the first stage of labor and then turn to the optimal (OA) position. But, some remain in this position, which can make labor difficult, resulting in emergency C-section. This fetal position can prolong your labor, lead to instrumental interventions, severe perineal tears or a C-section (3).
3. Occiput transverse (OT)
The baby lies sideways in the womb. If she fails to turn to the optimal position at the time of delivery, then a C-section becomes necessary. During the vaginal examination, the doctor can sometimes feel the shoulder, or the arm, elbow or hand prolapsing into the vagina. This position also poses the risk of umbilical cord prolapse, in which the umbilical cord comes out before the baby. As per a study, the incidence of a cord prolapse in transverse lie position is around 9% (4), which is a medical emergency and needs an immediate C-section. In some cases, assisted delivery is carried out by rotating the baby manually or using forceps or vacuum to turn the baby into the ideal position.
4. Breech position
The baby is positioned with her head up and buttocks pointing towards the birthing canal. This occurs in one out of 25 full-term deliveries. There are three different variations of breech presentations: i. Complete breech: The buttocks point towards the birthing canal with the legs folded at the knees and the feet positioned near the buttocks. This position increases the risk of umbilical cord loop in a vaginal delivery. Moreover, the cord could pass through the cervix before the head, causing injuries to the baby. ii. Frank breech: The buttocks point towards the birth canal with the legs stretching straight up and feet reaching the head. This can also lead to umbilical cord loop, causing injuries to the baby while attempting a vaginal birth. iii. Footling breech: The baby’s buttocks are downwards, with one of her feet pointing towards the birthing canal. This can cause an umbilical cord prolapse that could even cut off the blood supply and oxygen to the fetus.
5. Umbilical cord presentation
During this, the umbilical cord comes out first through the birthing canal (5). However, there is a difference between umbilical cord presentation and prolapse based on the condition of the uterine membrane. Whereas a cord presentation happens when the umbilical cord enters the birthing canal before the water breaks, a cord prolapse occurs after the water breaks, which calls for an immediate C-section. The positions are influenced by the health condition of the mother and the baby.
What Are The Risk Factors For Having A Difficult Fetal Position?
The below factors increase the risk of fetal malpositions (6):
Maternal factors:
Fetal factors:
These factors increase the likelihood of having an unsuitable fetal position but you don’t have to lose hope.
Can The Fetal Position Be Corrected?
Yes. There are two ways to correct the position of your baby. They are described below:
1. External cephalic version (ECV)
This medical procedure is undertaken after 37 weeks of pregnancy. The technique involves rotating the baby by applying pressure on the abdomen. The doctor places one hand over the head of the baby and the other hand on the buttocks to turn her to the optimal position. During this procedure, the heartbeat of the baby will be closely monitored using an ultrasound. In the case of any discrepancy in the fetal heart rate, the procedure will be stopped immediately. This procedure may or may not work. Studies show that about 1 in 1,000 women goes into labor after an ECV while about 1 in 200 women need an immediate C-section (8).
ECV is not recommended in the case of:
Multiple pregnancies Unusual shape of uterus Recent vaginal bleeding Low levels of amniotic fluid Placenta previa Complicated pregnancy
2. During labor
Most babies turn to an ideal birthing position with the onset of labor. If it doesn’t happen, if the baby doesn’t engage during labor, or if the shape of the pelvis is not favorable for vaginal birthing, then a Cesarean-section is performed.
How Is Belly Mapping Done?
Belly mapping is a method for you to track the position of your baby. You can do this from the eighth month of pregnancy. However, make sure to talk to your doctor before doing it. Things you require: A marker (the ink stain should be easy to remove) How to do:
Lie down, draw a circle on your tummy and divide it into four parts.
Feel the movements of the baby. Try to feel the baby’s head by slightly putting pressure on your abdomen. The point where you feel a ball like feature, mark it as the head on your belly.
Use a fetoscope to hear your baby’s heartbeat and mark the point. You will feel a long hard mass, which indicates the back of your baby. The heart is the part of this long mass.
Next, try to find the bum, which feels like a hard part. Mark this point on your belly.
Now feel the kicks and wiggles as they give you a clue about the location of the baby’s legs and knees. Mark it too.
Join all the points you have marked to find the position of your baby.
Belly mapping is complicated, and you may or may not be able to track the baby’s movements accurately. Therefore, you may club it with a few other ways.
Other Ways To Know The Position Of The Baby
Here are a few indications: These are just an assumption and a way to get connected with the baby. They do not replace your doctor’s advice.
