After someone has a cesarean section, they often wonder if they will always have to have a cesarean for future deliveries. While “once a cesarean, always a cesarean” is a common belief, it is not valid from a scientific standpoint. Neither is the assertion that the risks don’t increase with multiple prior cesareans. The truth is, vaginal birth after three cesareans (VBA3C), as well as vaginal birth after multiple cesareans (VBAMC), is an option for some people. Understanding what the research says, and acknowledging what we don’t know, is an important starting point for those evaluating their options and health care professionals alike.

How much information do we have about the risks of VBA3Cs/VBAMC?

The honest answer is that we do not have much information. Only a handful of studies have been published on VBA3C/VBAMC, and the strength of their findings is limited because they included a small number of women.

The honest answer is that we do not have much information on VBAMC.

Among the couple of thousand women with three or more prior cesareans included in these studies, only a fraction of them planned a vaginal birth. The largest study included 241 women who planned a vaginal birth after three or more cesareans. (1)

Additionally, studies often combine vaginal birth after two cesareans (VBA2C) with VBA3C/VBAMC, making it impossible to break out the risk among higher-order VBACs.

What do we know about the risks of opting for a repeat cesarean section?

Cesarean sections do pose risks to both the birthing parent and baby. They are associated with common minor complications and life-threatening risks, including excessive bleeding, blood clots, injury to other organs during surgery, injuries to baby, future risks with abnormal placentas (previa and accreta), and infection. As the number of cesareans increase, so do some of these risks.

Scheduling a repeat cesarean and avoiding labor does not necessarily eliminate risks. For example, one large study of planned cesareans reported the risk of needed hysterectomy as 0.9% (1 in 111) during the third cesarean and 2.41% (1 in 41) in the fourth cesarean. (2)

The risk of requiring a large blood transfusion also grows from 0.77% (1 in 130) in the third cesarean to 1.59% (1 in 63) in the fourth. (2) Placenta accreta, when the placenta abnormally attaches to the uterine wall, increases from 0.57% (1 in 175) in the third cesarean to 2.13% (1 in 47) in the fourth. (2)

The risk of placenta abnormalities, length of operative time, length of hospital stay, and rate of uterine infection all increase with each cesarean.

The risk of placenta abnormalities in future pregnancies, length of operative time, length of hospital stay, and rate of uterine infection all increase with each cesarean. (2)

Keep in mind that these are the rates among planned elective repeat cesareans which occurred simply because there was a prior cesarean. There was no medical reason for these cesareans to occur. (2) We also see higher rates for many of these complications when a medical reason develops during a planned VBAC that requires a cesarean. (3)*

Maternal birth complications in pregnancies following cesarean vary by how the person delivers. After one or two prior cesareans, VBACs have the lowest rates of complications, followed by planned cesareans, and then by those who plan a VBAC but have an unexpected repeat cesarean during labor (also called cesarean birth after cesarean or CBAC). (3)

What do the limited studies on VBA3C/VBAMC say?

The largest study we have, published in 1994 by Miller and team, reported that among those who planned a vaginal birth after three or more cesareans, 79% had one. For comparison, among those who planned a VBA1C (vaginal birth after one cesarean), 83% had a vaginal birth as did 75% of those who planned a VBA2C.

Miller reported a VBAMC uterine rupture rate of 1.2%. Some point to this study as evidence of the low uterine rupture rate associated with labor after three or more cesareans, however, transparency and clarity here is really important.

Only 241 people in his study planned a VBAMC and studies need several hundred people, and ideally a couple thousand, in order to report uterine rupture rates accurately.

So, we cannot say whether this uterine rupture rate of 1.2% is a true reflection of the risk. It may in fact be higher or lower than reported in this small study.

Miller reported that no babies died among the 241 that planned a vaginal birth after three or more cesareans. Again, a sample of 241 people is not enough to accurately report that outcome.

What this all means is this: no one can really say what the risks are.

There may be other risks associated with VBAMC; Miller did not report on other potential outcomes like oxygen deprivation to the baby or rates of excessive bleeding or hysterectomy among mothers.

While there are other studies on VBAMC, their sample sizes are even smaller, making their conclusions even weaker:

• • A 2010 study included 89 people planning a vaginal birth after three or more cesareans. (4)
  • A 2003 study had 4 people planning a vaginal birth after three cesareans. (5)
  • A 2006 study included 104 people with three or more prior cesareans but didn’t break out outcomes for this group by the number of prior cesareans. (6)

As a result, we don’t have strong data on VBAMC outcomes among birthing people or their babies.

What this all means is this: no one can really say what the risks are associated with labor after three or more cesareans. 

What do national guidelines say about VBA3C/VBAMC?

The American College of Obstetricians and Gynecologists (ACOG) simply states that data regarding risks for planned vaginal birth after two or more previous cesareans is limited. (7)

If ACOG’s goal was to risk out VBA3C/VBAMC, then they would have used plain language to make that intention clear.

Many believe since ACOG only explicitly mentions one or two prior cesareans, that means anything above and beyond that is outside of guidelines.

However, we must remember that ACOG is not shy about making recommendations. If their goal was to risk out VBA3C/VBAMC, then they would have used plain language to make that intention clear. They did not do that.

Do providers attend VBA3C/VBAMC?

How a provider approaches VBA3C/VBAMC depends on multiple considerations. In the absence of hard evidence, how should they navigate communicating the option of VBA3C/VBAMC versus repeat cesarean to birthing families?

We believe the best care occurs at the intersection of the evidence and autonomy. In the end, transparency is key. We have to be honest about what the evidence does, and does not, say. We also have to be clear that even when we don’t have solid evidence, the ultimate decision on how to birth lies with the pregnant person.

The reality is most physicians and midwives do not attend VBA3C/VBAMC for an variety of reasons that may not be about evidence, but rather policy or regulation. As a result, many women who want to labor after multiple cesareans have to travel long distances in order to find a supportive provider.

It’s also important to address the role that training and professional support have on VBAC access. In the video below, Dr. Craig Klose discusses the merits of vaginal birth after cesarean and the various factors that may impede women obtaining VBAC.

Notice Dr. Klose’s comments on VBAC after multiple prior low transverse cesareans (LTC). To sum, he says that he was taught that multiple LTCs were “no biggie” and he has attended up to VBA5C. This is the power of training and context! Dr. Klose is not alone and there are physicians, and midwives, across the US who attend VBAMC. It’s important to normalize honoring bodily autonomy as that is the foundation of health care including maternity care.

Unfortunately, some medical students are taught that VBAC, even after one cesarean, is dangerous even though ACOG’s guidelines encourage access. This is why it is so important for parents and professionals alike to learn the facts and not believe information simply because the source was someone you respect. Even people with the best of intentions can get it wrong. Let’s also normalize learning, growing, and doing better rather than blindly defending what we have always done.

The most important thing for parents to know about VBA3C/VBAMC

Every decision parents will make surrounding their pregnancy and childbirth has risks and benefits. If someone is thinking about a VBA3C/VBAMC, there are many things to consider, including how many more children they want to have.

Knowing what the research says is one thing to consider, but given that so few studies have been published on VBA3C/VBAMC, we just don’t have good data. So the most important thing for parents to remember is that this is an area of unknown risk. Keep in mind that even in these situations, people still have the right to make their own medical decisions.

The most important thing for parents to remember is that this is an area of unknown risk.

So as parents consider their options, we suggest checking in with themselves about weighing the unknown risk of VBA3C/VBAMC with the known risks and benefits of multiple cesareans. The limited evidence we have says that 79% of those who plan a vaginal birth after three or more cesareans will have one, and as we don’t have firm data on the likelihood of uterine rupture, we can’t say for certain where that particular risk lies.

The bottom line is, there is not enough information available to make a decision on whether or not to plan a VBA3C/VBAMC based solely on statistics.

Ultimately, how someone gives birth is their choice and their right. In exercising that choice, they take on a measure of personal responsibility for their health care outcomes.

Are you a perinatal professional who wants to learn more about this topic? We dive into all the details in our continuing education training, “What We Know About VBA3+C” (approved for 1.3 nursing contact hours) available through VBAC Facts® Professional Membership.

If you are a parent who wants to know what the VBAC evidence really says, so you can confidently plan your victorious VBAC, check out our course for parents: “The Truth About VBAC™ for Families.”

Jen

* I do refer here to older studies, but newer research is not as robust. The newer research relies on smaller groups of people and/or birth certificate data, doesn’t break out complications for higher numbers of repeat cesareans, and does not control for complicating factors like induction, induction agent, scar type, etc.

Resources Cited

2. Silver, R. M., Landon, M. B., Rouse, D. J., & Leveno, K. J. (2006). Maternal Morbidity Associated With Multiple Repeat Cesarean Deliveries. Obstetrics & Gynecology, 107(6), 1226-1232.

3. Landon, M. B., Hauth, J. C., & Leveno, K. J. (2004). Maternal and Perinatal Outcomes Associated with a Trial of Labor after Prior Cesarean Delivery. New England Journal of Medicine, 351, 2581-2589.

4. Cahill, A., Tuuli, M., Odibo, A., Stamilio, D., & Macones, G. (2009). Vaginal birth after caesarean for women with three or more prior caesareans: assessing safety and success. BJOG, 117, 422-428.

5. Spaans, W. A., van der Vliet, L., Roell-Schorer, E., Bleker, O. P., & Roosmalen, J. (2003). Trial of labour after two or three previous caesarean sections. European Journal of Obstetrics & Gynecology and Reproductive Biology, 110, 16-19.

6. Landon, M. B., Spong, C. Y., & Tom, E. (2006). Risk of Uterine Rupture With a Trial of Labor in Women with Multiple and Single Prior Cesarean Delivery. Obstetrics & Gynecology, 108, 12-20.

7. American College of Obstetricians and Gynecologists. (2019). ACOG Practice Bulletin No. 205: Vaginal birth after cesarean delivery. Obstetrics & Gynecology, 133(2), e110-e127.