By Pam Vireday

There is no argument amongst professionals and experts in maternal infant health that the cesarean rate in many places around the globe is unnecessarily high and may do more harm than good. One of the best ways to bring down the cesarean rate is to prevent the primary cesarean and support vaginal births after cesareans when appropriate to do so. In the USA, a baby in the breech position is often stated as a reason for a cesarean delivery, for first time parents, parents who have previously given birth vaginally before and also for those who are birthing after a cesarean. Today, Pam Vireday, an occasional contributor to Science & Sensibility takes a look at the evidence for external cephalic versions and their application to families who are birthing after a cesarean. Why is there so much resistance from health care providers to counseling families on what the evidence demonstrates external cephalic versions for people who have birthed by cesarean before? Sharon Muza, Community Manager, Science & Sensibility.

Introduction

An External Cephalic Version (ECV, or turning the baby manually to a head-down position) is one option open to people whose babies are breech. However, if a person has had a prior cesarean, they may be told that this is not an option for them. The evidence does not support excluding those with a prior cesarean from an External Cephalic Version. It's time for obstetric societies to update their guidelines about this, and it's time for more providers to routinely offer ECV.

Background

The main benefit of External Cephalic Version is that it is often successful in getting the baby head-down, and a head-down birth is usually less risky than a breech birth. Although many breech babies can be born vaginally just fine (especially those that meet certain criteria and/or are attended with alternate positioning), there are some increased risks to be aware of.

As a result, many care providers these days strongly prefer a cesarean or even schedule one automatically with a breech baby. Because some facilities do not "allow" Vaginal Birth After Cesarean (VBAC), this can mean that all future babies must also be born by cesarean. Therefore, getting the baby head-down via an External Cephalic Version can help prevent not just the first cesarean, but many automatic repeat cesareans and the serious complications that can happen with them. Jen Kamel covered one of these serious complications, placenta accreta, on Science & Sensibility previously.

Of course, like everything, ECV has both benefits and risks. The risks of ECV include premature labor, placental abruption (placenta detaching too early), hemorrhage, or fetal distress. Although real, these risks are relatively rare, usually less than 1%. Obviously, sometimes ECV is also contraindicated. Most clinicians agree that ECV should not be attempted in the presence of pre-existing fetal distress, placenta previa, placental abruption, premature rupture of membranes, and certain uterine malformations. Low amniotic fluid levels may also be a relative contraindication.

A good review of the benefits and risks of ECV can be found here. Basically, ECV is able to turn babies head-down most of the time without many complications, and thus prevents many cesareans that would otherwise happen. This is important because cesarean rates are so high; ECV is quite an effective way to reduce the number of cesareans and probably many cases of resulting abnormal placental attachment.

Astonishingly, though, research shows that ECV is not used that much in many areas, despite its relative success rate and potential for lowering the cesarean rate. Often, doctors don't even tell people that ECV is an option. They just schedule a cesarean and discourage people from exploring other options. One study from New Zealand estimated that only 26% of eligible patients with breech presentations were referred for ECV.

The situation is even worse if someone has had a prior cesarean. For those with a scarred uterus, it's even harder to get an ECV because doctors have been taught that it's too dangerous.

The Controversy

People whose babies are breech and have a history of a prior cesarean are often told that ECV is simply not a choice for them because manipulation done during an ECV might make the uterus rupture along the scar from the prior cesarean.

The problem is that there is no actual proof that this is a substantial risk. No study has found this to be a problem, but just the mere fear of the possibility has led to its denial for this group. Currently, you can still find recommendations online that list prior cesarean (or any prior uterine surgery) as a contraindication to even attempting an ECV. However, a policy of no External Cephalic Version for people with a prior cesarean is not supported by research. There are a number of studies, including some very recent studies, that suggest that people with a prior cesarean SHOULD have the option to have an External Version if they want it.

The latest study (Weill 2016) had 158 women in the study group and found no increase in complications in the group with a prior cesarean. The success rate of ECV in this group was good (117/158, or 74%), and only 12 of these patients ended up with a cesarean during labor. That means that using ECV in the prior cesarean group prevented 105 automatic repeat cesareans. The authors summarized their findings this way:

"ECV may be successfully performed in patients with a previous caesarean delivery. It is associated with a high success rate, and is not associated with an increase in complications."

Similarly, another recent study (Burgos 2014) found no increased rate of complications in the group with a prior cesarean. The authors concluded:

"Uterine scar should not be considered a contraindication and ECV should be offered to women with previous caesarean section with breech presentation at term."

Another study (Abenhaim 2009) also found no increase in complications in those with a prior cesarean who had an ECV. The authors stated:

"Concern about procedural success in women with a previous cesarean section is unwarranted and should not deter attempting an external cephalic version."

However, both the Royal College of Obstetricians and Gynaecologists (RCOG) and the American College of Obstetricians and Gynecologists (ACOG) still hesitate to endorse ECV after prior cesarean. They say that there is not enough research to prove that it is safe. They point out that many of the studies on ECV and prior cesarean are fairly small, which limits their power.

That is a fair point. It's true that most studies have been relatively small and we don't have a huge pool of data to pull from, but taken together the results are quite encouraging.

One older review (Sela 2008) did a search of previous studies to pool the results. They found a total of 124 patients who had an ECV after prior cesarean. They added 42 patients from their own database. Adding in the 36 from the Abenhaim 2009 study, 70 from the Burgos 2014 study, and 158 from the Weill 2016 study, you get a total of 430 patients who have been documented to have an ECV after prior cesarean - all without any poor outcomes.

What this means is that there isn't ANY evidence to prove that ECV is unsafe in those with a prior cesarean. While the data pool is still somewhat limited, so far ALL of it supports ECV after prior cesarean.

Yet ACOG's recently revised 2016 guideline on ECV states, "Having had a previous cesarean delivery is not linked with lower rate of success; however, whether it magnifies risk for uterine rupture is not known." They cite only two studies from 1991 and 1998 and state, "Larger studies would be needed to establish the risk of uterine rupture." This ignores all the recent studies on ECV. This cavalier omission will continue to lead many care providers to continue to deny ECV to those with prior cesareans.

Although more research is needed, the bottom line is that the accumulating evidence certainly suggests that an ECV after a prior cesarean is not unduly risky and is a reasonable choice that should be offered to those who want it.

A more reasonable view of the evidence has led the SOGC (the Society of Obstetricians and Gynaecologists of Canada, the Canadian version of RCOG and ACOG) to state:

"External cephalic version is not contraindicated in women with a previous Caesarean birth."

It's time for ACOG and RCOG to recognize that they are basing their guidelines more on fear than on the latest evidence and update their guidelines accordingly. Bravo to the Canadians for leading the way on this issue.

More research should be done - an excellent question is WHY hasn't more been done by now? My best guess is that it reflects the exaggerated fears of the care providers rather than a reasoned response. But given the absence of poor outcomes up till now, research on this topic should be expanded and in the meantime, ECV should be available to those with a prior cesarean.

In addition, it is time for more care providers to offer ECV as an option across the board. This is a sadly underused procedure that could certainly greatly impact cesarean rates and maternal morbidity, both by preventing the first cesarean and lowering the rate of automatic repeat cesareans that follow.

For those families with a breech baby who were hoping to have a vaginal birth after a cesarean, what have been the options in your community? Share with us in the comments section below. - SM

References

Abenhaim, H. A., Varin, J., & Boucher, M. (2009). External cephalic version among women with a previous cesarean delivery: report on 36 cases and review of the literature. Journal of perinatal medicine, 37(2), 156-160.

Burgos, J., Cobos, P., Rodriguez, L., Osuna, C., Centeno, M. M., Martínez, Astorquiza, T., & Fernández' Llebrez, L. (2014). Is external cephalic version at term contraindicated in previous caesarean section? A prospective comparative cohort study. BJOG: An International Journal of Obstetrics & Gynaecology, 121(2), 230-235.

De Meeus, J. B., Ellia, F., & Magnin, G. (1998). External cephalic version after previous cesarean section: a series of 38 cases. European Journal of Obstetrics & Gynecology and Reproductive Biology, 81(1), 65-68.

Flamm, B. L., Fried, M. W., Lonky, N. M., & Giles, W. S. (1991). External cephalic version after previous cesarean section. American journal of obstetrics and gynecology, 165(2), 370-372.

Schachter, M., Kogan, S., & Blickstein, I. (1994). External cephalic version after previous cesarean section' - a clinical dilemma. International Journal of Gynecology & Obstetrics, 45(1), 17-20.

Sela, H. Y., Fiegenberg, T., Ben-Meir, A., Elchalal, U., & Ezra, Y. (2009). Safety and efficacy of external cephalic version for women with a previous cesarean delivery. European Journal of Obstetrics & Gynecology and Reproductive Biology, 142(2), 111-114.

Weill, Y., & Pollack, R. N. (2016). The efficacy and safety of external cephalic version after a previous caesarean delivery. Australian and New Zealand Journal of Obstetrics and Gynaecology.

Image source:

Grundriss zum Studium der Geburtshülfe 1902, Ernst Bumm and Albrecht Mayer

Successful External Cephalic Version (ECV) - Turning a breech baby in just 2 minutes!' by Liam Muckleston

About Pam Vireday

Painting by Mary Cassatt, 1844- 1926. (public domain) Image from Wikimedia Commons.

Pam Vireday is a childbirth educator, writer, woman of size, and mother to four children. She has been collecting the stories of women of size and writing about childbirth research for 19 years. She writes at www.wellroundedmama.blogspot.com and www.plus-size-pregnancy.org.

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