Overview of External Cephalic Version
In the last ten years, the overall rate of cesarean sections – sometimes known as C-sections, which is a type of surgery used to deliver a baby – has risen from around 23% to 34% worldwide. One of the primary reasons for having a C-section is fetal malpresentation, meaning the baby is positioned in an unusual way in the womb. This accounts for around 17% of all C-sections.
About a quarter of all babies are positioned in a breech presentation (feet-first, as opposed to the usual head-first) at 28 weeks into the pregnancy. However, by the time a mother reaches full term (around 40 weeks), this decreases to 3-4%. These days, most babies that are still in a breech position when labor starts are delivered by C-section.
In a bid to safely lower the number of C-sections, especially for first-time mothers, health workers and hospitals are considering alternatives. One example of this is an external cephalic version (ECV). An ECV is a procedure which attempts to manually turn the baby into a correct, head-first position while still in the uterus. This can be tried after 37 weeks of pregnancy if the baby is in a breech, or in an oblique or sideways position.
ECV is successful about 60% of the time, which makes it a cost-effective alternative that could help lower C-section rates. It is especially useful in areas where health services are limited or the surgery of a C-section may be unsafe or unavailable.
Anatomy and Physiology of External Cephalic Version
ECV, or External Cephalic Version, is a method doctors use to try and turn a baby before birth when the baby is not positioned head-down. When a baby’s position is not head-down, it can be a breech presentation, or the baby can be in a transverse or oblique lie.
In a breech presentation, the baby is positioned to come out feet or bottom first. There are three kinds of breech presentation. In a complete breech, the baby’s bottom is down, with their hips and knees bent so their legs are folded. A frank breech is when the baby’s bottom is down, but their legs are straight up, with their feet near their head. A footling or incomplete breech is when one or both feet are the lowest part of the baby’s body and set to emerge first.
A transverse lie is when the baby is positioned sideways in the womb- across the mother’s belly. The baby’s spine is at a right angle to the mother’s spine. The baby’s head may be positioned to the mother’s right or left side, and the baby may be facing up or down.
An oblique lie means that the baby lies diagonally in the uterus, so their head is positioned to be in the lower right or left side of the mother’s belly. This position, however, is not exclusive and can change.
Why do People Need External Cephalic Version
A procedure known as External Cephalic Version (ECV) can be recommended to certain patients whose baby is not in the correct position for birth. This procedure is typically considered for those who are 36 weeks or more into their pregnancy and the baby isn’t positioned head-first in the womb, and for those who don’t have conditions that rule out a normal vaginal delivery, such as placenta previa (placenta blocking the cervix), vasa previa (blood vessels blocking the cervix), or a past cesarean birth with a vertical cut.
The baby’s health should be stable, and a nonstress test (a check on the baby’s heartbeat) is usually advised before the procedure. Although ECV can be done once a woman is 36 weeks pregnant, some doctors prefer to wait until the 37th week to make sure the baby is mature enough if born.
The chances of ECV being successful are higher in women who have had more than one pregnancy, when the baby is positioned bottom-first or sideways or at an angle, the baby’s head hasn’t dropped down into the pelvis yet, there’s enough fluid around the baby in the womb, and the placenta is attached to the back of the uterus. However, ECV might be less successful in women with their first pregnancy or those having certain placenta positions, those who are overweight, who have a low amount of fluid around the baby in the womb, whose water has broken, or whose baby is very light in weight, head-down but already set deep into the pelvis, positioned with legs straight out (frank breech), or facing the mother’s back.
Doctors often use a medication called terbutaline, which relaxes the muscles of the uterus to improve the chances of success with ECV. Moreover, there’s no clear consensus whether using regional anesthesia (numbing certain areas) helps in increasing the success rates of ECV.
When a Person Should Avoid External Cephalic Version
Conditions that prevent a woman from delivering her baby vaginally also prevent her from having an ECV (External Cephalic Version), which is a technique to turn the baby around in the womb before birth. These conditions could include having a placenta that covers the cervix (placenta previa), blood vessels obstructing the baby’s path (vasa previa), an active outbreak of genital herpes, or a history of a specific type of cesarean delivery known as classical cesarean delivery. However, if a woman had a low transverse cesarean (a kind of cesarean section with a horizontal cut) before, this will not always stop her from having ECV. The chances of success of ECV for women who had previously had a cesarean birth range from 50% to 84%. In the trials that were conducted, no cases of the womb rupturing during ECV were reported among these patients.
ECV cannot be safely performed if the mother is carrying more than one baby. An exception exists for twin pregnancies that are appropriate for a special delivery method known as breech extraction (birth of a baby feet first instead of head first).
ECV also needs to be carefully considered and may not be as successful in cases where there’s not enough amniotic fluid (severe oligohydramnios), if the monitoring of the baby shows concerns, if the baby’s head is tilted back too far, if there is a significant abnormality with either the baby or the womb, if the baby is growing slowly (fetal growth restriction), and if the mother has high blood pressure. In such situations, ECV might not work and may cause harm to the baby.
If a pregnant woman who could otherwise have ECV comes to the hospital in early labor with her baby in the wrong position, ECV might be a good option if the baby’s presenting part is not yet in the pelvis, the index for the amount of amniotic fluid is normal, and there are no other reasons why she couldn’t have ECV or deliver vaginally. From 1998 to 2011, studies showed a 65% success rate for ECV performed on carefully chosen patients upon admission for labor and delivery. In these cases, ECV significantly reduced the need for a cesarean section and chances of a hospital stay longer than 7 days compared to patients whose babies remained in the breech position at the time of delivery.
Equipment used for External Cephalic Version
An external cephalic version (ECV) – a procedure to turn the baby in the womb to a head-first position – must only be conducted in places where immediate access to operations like a cesarean section are possible. This means all the equipment needed for a cesarean section, including tools for anesthesia, should be available when conducting an ECV.
The doctors also need to have medicines called tocolytic agents, which are used to stop premature labor, a bedside ultrasound machine to see images of the baby in the womb, and external tools to monitor the baby’s heartbeat. After the ECV, the doctor needs to check the baby’s health; a nonstress test is usually the chosen method. This test measures the baby’s heart rate in response to its movements. If this test can’t be done, the doctor may use Doppler indices. This technology uses sound waves to estimate the speed and direction of blood flow in vessels like the umbilical artery, middle cerebral artery, and ductus venosus, which are all important for the baby’s health.
Who is needed to perform External Cephalic Version?
To carry out a procedure known as ECV (External Cephalic Version), which is a method used to turn the baby from a breech position (bottom or feet first) to a head-down position before labor begins, you typically need a specialist doctor who cares for pregnant women, known as an obstetrician, and a nurse who specializes in childbirth, referred to as a labor and delivery nurse.
ECV should only be done in a place where there’s quick access to a cesarean delivery service. Performing a cesarean delivery, a surgery used to deliver a baby through a cut in the mother’s belly and uterus, calls for several medical professionals:
- The obstetrician, a doctor who specializes in pregnancy and childbirth.
- A surgical first assistant, an expert who aids the obstetrician during the operation.
- Anesthesia personnel, a professional who ensures you’re asleep and don’t feel pain during the surgery.
- A surgical technician or operating room nurse, who prepares and maintains the surgical equipment and room.
- Circulating or operating room nurse, who helps all members in the surgical team to create and maintain a safe, comfortable environment.
- Pediatric personnel, doctors or nurses who specialize in the health care of babies and children.
Remember, labor and delivery nurses can also take on the roles of surgical technicians, circulating nurses, or operating room nurses during a cesarean delivery. This is because these nurses are skilled in different aspects of childbirth and can support various roles needed for the surgery.
Preparing for External Cephalic Version
Before any attempts are made to turn a baby in the womb (a procedure known as ECV), doctors need to explain what will happen, any risks involved, and get a patient’s agreement to go ahead with the treatment. This may also include discussions about using medicines to relax the womb (tocolysis) and for pain relief (neuraxial analgesia). Certain doctors might also discuss the possibility of a potential emergency C-section, although this isn’t done everywhere. Another part of the pre-ECV process is doing an ultrasound check. This allows the doctor to see which way the baby is facing, spot any issues with the baby or womb, find out where the placenta is, and measure the amount of amniotic fluid. A lot of doctors also use a nonstress test to make sure the baby is doing okay before the procedure.
Current research supports giving a patient a small dose of a medicine called terbutaline underneath the skin about 15 to 30 minutes before trying to turn the baby. However, this same research doesn’t suggest using medicines called calcium channel blockers or nitroglycerin to relax the womb before ECV. Some studies do show higher ECV success rates when local anesthetic is given into the space around the spinal cord, but there isn’t enough data to suggest that absolutely all patients should have this. It might be more helpful in cases where relaxing the womb wasn’t enough to make the ECV work.
How is External Cephalic Version performed
If a pregnant woman has a baby that’s positioned feet-first (also known as a breech presentation) or sideways, a procedure known as an External Cephalic Version (ECV) can be used to try and turn the baby within the womb into a head-first position. This is how it works:
The pregnant woman lies down and a small, supportive wedge is placed under one side of her back to take some pressure off her blood vessels. The doctor typically uses both hands for this procedure.
If the baby is breech, one hand puts a lifting pressure on the part of the baby presenting itself at the pelvis (their bottom if they’re breech), while the other hand puts a downward pressure on the back of the baby’s head, encouraging a forward roll. If this doesn’t work, they might try a backwards roll.
If the baby is sideways (known medically as transverse or oblique presentation), the doctor also uses similar techniques to guide the baby’s head toward the pelvis.
Throughout the procedure, either Doppler ultrasound (a test that uses soundwaves to take pictures and check blood flow) or real-time ultrasound (which provides live video images) are used to make sure the baby is okay. If the procedure causes a significant decrease in the baby’s heart rate, severe discomfort to the mother, or if the baby doesn’t seem to be turning easily, the doctor will stop.
After either a successful or unsuccessful ECV, the baby’s heart rate should be closely observed for an hour or less. If the mother’s blood type is Rh negative, medication should be given to prevent potential problems related to Rh factor – a protein found on red blood cells.
Even if the ECV is successful, it’s not recommended to immediately induce labor to prevent the baby from moving back into the original position. If the first attempt at ECV doesn’t work, the doctor can try again later or during the same appointment.
Possible Complications of External Cephalic Version
Only about 1% to 2% of people who have an External Cephalic Version (ECV) face complications. This procedure is done to turn a breech baby (where the baby’s feet or buttocks are pointed towards the birth canal instead of its head) in the womb to the right position before labor starts. The most typical issue that can occur during ECV is changes in the baby’s heart rate, particularly a slower heart rate. However, this situation usually gets better once the procedure ends.
There are also more severe complications, but they are quite rare (occurring in less than 1% of cases). Some possible severe complications are breaking of the water bag too early, umbilical cord coming out before the baby, vaginal bleeding, the placenta getting detached from the wall of the uterus, blood mixing between mother and baby, and stillbirth. Some of these complications may require a sudden cesarean section, which means delivering the baby through surgery. Because of these risks, some doctors may choose to perform the ECV in an operating room for immediate access to emergency care if needed, but this isn’t a universal practice.
ECV can cause temporary changes in blood flow to the placenta. Despite this, these changes don’t appear to harm uncomplicated pregnancies. A recent study found no significant differences in blood flow in the brain or the ductus venosus (a blood vessel in a fetus that bypasses the circulation to the lungs) in babies after ECV. All these babies stayed stable and could go home after the procedure.
What Else Should I Know About External Cephalic Version?
External cephalic version (ECV) is a procedure that doctors use to try to turn a baby from a breech position (feet first) to a head-down position for birth. Unfortunately, only around 20% to 30% of patients who could benefit from ECV actually get offered this treatment.
If ECV successfully turns the baby, it can greatly lower the chance of having a cesarean section, or C-section (a surgery to deliver the baby). However, even when successful, these mothers are still more likely to need a C-section compared to mothers whose babies are already in the head-down position and didn’t need ECV.
From a cost perspective, ECV is a good value if there’s a better than 32% chance it will work. In fact, ECV works over half the time (58%) and can reduce the need for a C-section by two-thirds. This means that the majority of mothers who have a successful ECV go on to have a normal vaginal birth.
