As is the case with vaginal birth after one cesarean, (VBA1C), vaginal birth after two cesareans (VBA2C) is a reasonable option that is often difficult for people to access. This difficulty is caused by fear and misunderstanding about the evidence and the risks. While I have addressed myths about VBA2C in the past, I wanted to explore this topic further. To help clear up all the confusion, here is an overview of the VBA2C evidence. 

VBA2C is mainstream

First, let’s be clear. VBA2C is a mainstream, evidence-based, reasonable option supported by national guidelines and medical studies. 

As the American College of Obstetricians and Gynecologists (ACOG) asserted in their 2019 VBAC Practice Bulletin No. 205, “given the overall data, it is reasonable to consider women with two previous low transverse cesarean deliveries to be candidates for TOLAC [trial of labor after cesarean] and to counsel them based on the combination of other factors that affect their probability of achieving a successful VBAC.” 

A prior vaginal birth is not required to plan a VBA2C 

In 2004, ACOG published VBAC guidelines which stated a prior vaginal delivery was “required” in order for someone to plan a VBA2C. This recommendation was removed in the subsequent guidelines published in 2010 and has not resurfaced again. 

Nevertheless, some clinicians still inform birthing people that unless they have a prior vaginal delivery, they can’t plan a VBA2C. Given that it can take upwards of 20 years for new evidence to make its way into clinical practice and hospital policy, I want to draw special attention to this obsolete requirement that can be a barrier to access. (Agency for Healthcare Research and Quality, 2001)

Prior vaginal delivery means higher VBA2C odds

While a prior vaginal delivery is no longer “required”, if someone has had a prior vaginal delivery, they are an especially good VBA2C candidate. This is because their risk of uterine rupture (one of the most serious potential complications of VBAC) has decreased, and their odds of a vaginal birth (VBAC) have drastically increased. (Mercer, 2008) 

If someone has had a prior vaginal delivery, they are an especially good VBA2C candidate.

In fact, one large study reported that the VBAC rate among those with one prior VBAC was 88%. This increased to 91% after two prior VBACs. This is significantly higher than the rate of 63% among those with no prior VBACs. (Mercer, 2008)

Please note, while the odds of vaginal delivery increases with each prior VBAC, the risk of uterine rupture does not decrease with each subsequent VBAC. The risk of uterine rupture significantly drops after the first VBAC, but it does not lower if more vaginal deliveries occur, nor does it ever return to the risk level of someone who has never had uterine surgery. (Mercer, 2008)

Overall odds for a vaginal delivery are high

Even without a prior vaginal delivery, once someone goes into labor after two cesareans, the odds of their having a VBA2C are good. One study reported rates similar to those with one prior cesarean, about 75%. (Macones, 2005)

Another study reported a significant drop from 74% after one cesarean to 67% after two. (Landon, 2006) But the largest systematic review of over 5,600 VBA2Cs reported only a modest drop from 77% to 72%. (Tahseen, 2010)

The largest systematic review of over 5,600 VBA2Cs reported only a modest drop in VBAC rates after one versus two prior cesareans: 77% to 72%.

While there is one recent study that reports much lower VBAC rates–only 39%–the authors of that study acknowledge that number reflected the low overall national VBAC rate rather than the physical ability of people to deliver vaginally after two prior cesareans. (Dombrowski, 2020)

In other words, in a climate where physicians may recommend a cesarean earlier than necessary for VBA1C, they may also follow that pattern for a planned VBA2C labor. That study reported that VBA2C rates were higher in hospitals that had higher level NICUs or where midwives attend births. 

VBA2C evidence is limited

When we look at the available evidence on VBA2C, we see that while there have been quite a few studies published, the number of people included in the studies varies greatly.

The largest recent studies were published by Macones et al in 2005, Landon et al in 2006, and Dombrowski et al in 2020. Macones and Landon are the two VBA2C studies cited in ACOG’s 2019 VBAC guidelines, whereas Dombrowski focused on all people who birthed after two cesareans in California between 2010 and 2012.

All three modern VBA2C studies were similarly sized, ranging from 975 to 1,228 people who labored after two cesareans.

All three studies were similarly sized, ranging from 975 who labored after two or more cesareans in Landon (871 of whom had two cesareans), to Macones and Dombrowski which respectively included 1,082 and 1,228 people who labored after two cesareans.

In fact, we have to go back to 1994 to get the next sizable study published by Miller which included 1,586 people who labored after two prior cesareans over the course of 10 years.

Given that we have this collection of small studies, in 2010, Tasheen combined them all into a larger study called a systematic review. This enables us to merge the power of the existing research comparing VBA1C with VBA2C outcomes, as well as VBA2C versus scheduled third cesarean outcomes. Tasheen included 5,666 people who labored after two cesareans. What did these studies find?

VBA2C uterine rupture risk is low

Some studies don’t report a difference in uterine rupture risk between VBA1C and VBA2C. Others do. As a result, it is hard to say definitely how the risk evolves for those who have two prior cesareans. It’s likely that the risk increases but how much it does, no one can say for sure. Let’s look at the evidence.

Reported uterine rupture rates during planned VBA2C range from 0.9% to 1.8%.

Macones (2005) reported a uterine rupture rate of 1.8% among the 1,082 who labored after two cesareans. This was significantly higher than those laboring after one cesarean, 0.9%.

Landon (2006) reported a uterine rupture rate of 0.9% among the 975 who labored after two or more cesareans. This was not statistically different from the 0.7% among those with just one prior cesarean. 

While Miller (1994) is quite old, it included 1,586 people laboring after two cesareans and reported a uterine rupture rate of 1.8%, the same as Macones. 

Tasheen (2010), which included Macones, Landon, Miller, as well as a smattering of smaller studies, reported that the risk of uterine rupture was higher after two cesareans: 0.7% after one cesarean versus 1.6% after two. 

VBA2C uterine rupture risk may even be lower than reported

As a result of Macones’ and Landon’s studies, most people believe the rate of VBA2C uterine rupture to be 0.9% to 1.8% and these are the figures cited in ACOG’s VBAC guidelines. But here’s the catch: those rates are influenced by high rates of induction and augmentation.

In these two studies, many labors were induced (started artificially by means of medication) or augmented (medication was given to speed up labor that was already in progress). We know that induction and augmentation likely increase the risk of uterine rupture. (ACOG, 2019) Therefore, it is likely that the reported 0.9% to 1.8% rate of uterine rupture is higher than the rate would be in non-induced or non-augmented labors.

Spontaneous labor in these studies means someone whose labor began and progressed naturally without the use of medications like Pitocin. So, let’s look at Macones and Landon. How many labored spontaneously? 

The often-cited uterine rupture rate after two cesareans of 0.9% – 1.8% is based on a 49% – 65% induction and augmentation rate.

In Macones’ study, only 35% labored spontaneously. In Landon’s, it was 51%, including people with two or more cesareans. (While Miller makes reference to the fact that a number of labors were induced and augmented, it does not provide further details. Similarly, while a number of labors were induced in Dombrowski’s study, they did not report the breakdown between induced/augmented and spontaneous labors.)

So, the often-cited uterine rupture rate after two cesareans of 0.9% – 1.8% is based on a 49% – 65% induction and augmentation rate. This is an important factor to consider anytime we discuss VBA2C.

As a result, it’s possible that the rate of uterine rupture during a spontaneous labor after two cesareans is lower than 0.9% – 1.8%. In fact, Macones revealed that of the 379 people who labored spontaneously, 3 had a uterine rupture for a rate of 0.8%. 

Can we say that the true risk of uterine rupture during a planned VBA2C is 0.8%? No. This is a single data point and with such a small sample size, we can’t lean into that number as the answer. Meanwhile, Landon, Dombrowski, and Miller did not reveal the rate of spontaneous uterine rupture.

So, we have a subset of 379 people from one study where we can clearly point to a rate associated with spontaneous labors. Such a small sample size is not strong evidence.

But with the knowledge that induction and augmentation potentially increases uterine rupture risk, it is reasonable to assert that the rate of uterine rupture during spontaneous labor could be lower than the 0.9% to 1.8% range reported by Macones and Landon.

However, as we do not have studies on spontaneous uterine rupture during a planned VBA2C, we don’t have solid data on the risk.

This is, again, where transparency is important. Being clear on what we know, and what we don’t, is essential especially when providers relay information to birthing people. It is fundamental to developing rapport and trust as well as navigating important decisions around labor and birth

Other VBA2C maternal and neonatal risks are low

What about other complications associated with planned VBA2C? Before we dive into that, let’s review a very important concept that influences not only how we communicate information, but how others receive it. That concept is the difference between relative risk and absolute risk.

Relative risk compares outcomes of different situations. Absolute risk tells us how often an outcome occurs. This is the difference between saying a specific risk “doubles” (relative risk) when it increases from 1% to 2%, or saying “The risk is 2% or 1 in 50” (absolute risk).

With VBA2C, there are a couple of ways to look at risk. First, how risk compares between those who labor after one cesarean versus those who labor after two cesareans.

A systematic review on VBA2C found that while maternal complications such as uterine rupture (0.7% vs 1.6%), blood transfusion (1.2% vs 2%), and hysterectomy (0.2% vs 0.5%) were relatively higher after two cesareans, “the absolute rates are small.” (Tahseen, 2010)

The risk of maternal complications during planned VBA2C are “small.”

The same pattern held true for neonatal outcomes. The rate of stillbirth, postnatal death, and injuries associated with oxygen deprivation increased from 0.05% to 0.09% for those laboring after one versus two prior cesareans. (Tahseen, 2010)

But how do outcomes compare between a scheduled third cesarean and a planned VBA2C? Risk of uterine rupture is clearly higher with a planned VBA2C (0.1% vs. 1.1%), but transfusion (1.7%), hysterectomy (0.6% vs. 0.4%) and NICU admission (8.9% vs 8.5%) were all similar. (Tahseen, 2010) 

For perinatal outcomes, the risk of stillbirth, postnatal death, and injuries associated with oxygen deprivation was higher with a VBA2C (0.09%) than with a scheduled third cesarean (0.01%), but the absolute risk was still quite low. The study concluded that the data on perinatal outcomes “does not indicate a significant difference between” VBA1C, VBA2C, and a scheduled third cesarean. (Tahseen, 2010) 

VBA2C is a “reasonable option” associated with “increased risk” that was “statistically small.”

The two largest modern studies included in this systematic review, as well as the review itself, concluded that while the relative risks were higher with VBA2C, the absolute risks were still low. Thus, VBA2C is a “reasonable option” (Macones, 2005) associated with “increased risk” that was “statistically small” (Landon, 2006) and people “should have the option of a carefully monitored vaginal delivery available to them” (Tahseen, 2010).

Further, Dombrowski reported that when comparing those who labored after two cesareans versus those who planned a third cesarean, there were no differences in maternal outcomes and only a “modest increase” in newborn complications (2.0% vs 1.4%).

This is why ACOG’s VBAC guidelines support access to VBA2C.

Medical evidence can be used to manipulate

Even though the medical evidence supports VBA2C, there are those who will take slices of this information and use it to encourage birthing families to schedule repeat cesareans. This is because people can look at the same study and the same numbers and do one of two things: be transparent about the findings and put it into perspective so that the audience can easily understand the facts and make their own decision, or magnify and highlight select risks to sway the audience toward a specific decision.

Many birthing people report being coerced into a second or third repeat cesarean by providers who exaggerate the risk of their baby dying during a planned VBA2C, so let’s talk a bit about that risk. Per our systematic review, the risk was higher with labor after two cesareans versus a third cesarean (0.09% vs 0.01%). Let’s think about how someone can communicate this information.

If we wanted to be transparent and honest, we could say that the relative risk was higher, but the absolute risk is quite low with both options.

If we wanted to deter someone from planning a VBA2C, we could focus on the relative risk: “The risk of your baby dying is nine times higher if you plan a VBA2C.” And that is a correct statement. 

If we wanted to be transparent and honest, we could say that the relative risk was higher, but the absolute risk–at 0.09% for labor after two cesareans and 0.01% for elective repeat cesareans–is quite low with both options. One could express the risk in another way. Rather than the abstract percentage of 0.09%, we might give a ratio–1 in 1,111–which further frames the small absolute risk.

Beyond that, we would explain, as the authors of this systematic review do, that the studies on which these numbers are based are 10 to 20 years old with “less-advanced neonatal facilities.” This means that these “neonatal morbidity figures may not be representative of current practice given considerable advances in neonatal care in recent years.” (Tahseen, 2010)  In other words, it’s likely that the current neonatal outcomes for planned VBA2C could be better than those reported in this 2010 systematic review. This is something to be aware of when looking at older VBAC data.

However, ignoring this context and nuance is exactly how some providers use published medical research to focus solely on the relative risk number and obscure the full picture in order to obtain “consent” for a third cesarean.

Induction is not contraindicated in VBA2C

Induction after two cesareans is not contraindicated per ACOG’s VBAC guidelines. This is a good thing, because in the absence of induction, when a medical indication arises that necessitates delivery, the only remaining option is a third cesarean. The option for an induction means that a vaginal birth could still occur, avoiding the risks associated with another surgical birth. Risks and benefits–including areas of unknown risk–must be discussed so birthing people can make the medical decisions that are best for them.

Are there any studies specifically on VBA2C induction? We were able to identify a small study of 152 VBA2C inductions which concluded that VBAC rates as well as maternal and neonatal outcomes were the same for those with one and two prior cesareans. Comparing an induced labor after two cesareans to a scheduled third cesarean, this study found that maternal and neonatal outcomes were similar. (Miller & Grobman, 2015)

Cesarean surgeries carry their own risks

Often when VBA2C is discussed between a provider and patient, the conversation is limited to the short-term risks of a labor after cesarean, like uterine rupture, hysterectomy, or blood transfusion. This holds true for the existing studies on VBA2C. However, several of those studies, including Macones, Landon, Dombrowski, and Tasheen, all mention the importance of considering long-term consequences, as well–especially when it comes to the risks of multiple repeat cesarean sections. 

The risks of placenta accreta and hysterectomy in particular are significant: “women having their fourth or more cesarean delivery had a 9- to 30-fold increased risk of placenta accreta and a 4- to 15-fold higher risk of hysterectomy.”

In fact, the risk of certain pregnancy, delivery, and postpartum complications increase with each cesarean birth. These include risks of serious placental abnormalities like placenta accreta (placenta abnormally attaches to the uterine wall) and placenta previa (placenta attaches close to, or over, the cervical opening), hysterectomy, large blood transfusions, surgical injuries (bladder, bowel, and ureters), ICU admission, infection, post-operative ventilator, operative time, and hospital stays. (Silver, 2006) 

The risks of placenta accreta and hysterectomy in particular are significant: “women having their fourth or more cesarean delivery had a 9- to 30-fold increased risk of placenta accreta and a 4- to 15-fold higher risk of hysterectomy.” (Silver 2006) 

Four years later, that same physician-researcher warns, “indeed, placenta accreta has now become the most common reason for cesarean hysterectomy in developed countries.” (Silver, 2010)

Further, scar tissue within the abdominal cavity, called “adhesions”, can develop after abdominal surgery like cesareans. Adhesions can increase with each subsequent surgery and can become an issue whether or not a person plans to have more children. For those who have another cesarean, adhesions are associated with longer operative times. This can increase blood loss and surgical injuries as well as potentially compromise neonatal outcomes in an emergency cesarean. (Morales, 2005; Greenberg, 2011)

“These long-term maternal [cesarean] complications must be factored into the risk/benefit ratio for women considering vaginal birth after cesarean delivery.”

Adhesions from a cesarean have also been associated with chronic pain (The National Institute of Diabetes and Digestive and Kidney Diseases, 2019) and bowel obstructions years after the surgery. (Abenhaim, 2018) Anyone with a history of cesarean birth who is experiencing symptoms consistent with a bowel obstruction should be screened immediately, given the risk of death associated with delayed diagnosis. 

How prevalent are adhesions? One study reported that 46% of those having their third cesarean had multiple adhesions (Nisenblat, 2006) and another found that 83% of those having their fourth cesarean had developed pelvic adhesive disease (Morales, 2005). 

As a 2010 article warns, “These long-term maternal [cesarean] complications must be factored into the risk/benefit ratio for women considering vaginal birth after cesarean delivery (VBAC).” (Silver, 2010)

While most people will not experience serious complications with repeat cesareans, this is also true among those who plan a VBA2C. 

The option of planned VBA2C has psychological implications 

It is really important for clinicians, friends, and family members to understand that the choice to have a VBAC is not just about a baby coming out of a vagina versus an abdominal incision.

It’s about being heard, respected, and seen. It’s about boundaries being respected. 

It’s about the birthing person feeling like they have some control over what happens to their body, and have the right to do so, rather than being forced to consent to things that they do not want or need. 

Within this space there is a risk of causing trauma or an opportunity to heal it.

It’s about feeling the power of one’s body… the power of everything their body can do. 

Within this space there is a risk of causing trauma or an opportunity to heal it. Right now, the system is causing trauma by leading people to believe their only option is another cesarean birth. Coercing them into multiple repeat cesareans by remaining silent on the risks those surgeries introduce is common and wrong. 

Feeling like you are trapped, overpowered, and ignored is not only a horrible setting in which to welcome your new baby, it’s also a recipe for increasing the risk of developing perinatal mood disorders in the postpartum period. (Beck, 2019; Bell, 2018; The Birth Trauma Association; Coates, 2019)

Planning a VBA2C can be challenging

Despite the evidence and guidelines supporting safety and access to VBA2C, many people in the US find planning one to be challenging. While 80% of people with no prior cesareans plan a vaginal birth, once someone has had a single cesarean, that number drops to only 20%. That’s right, only 20% of people plan a VBA1C. After two or more prior cesareans, that number drops further to 7%. (Curtin, 2015) 

Only 20% of people plan a VBA1C. After two or more prior cesareans, that number drops further to 2.9% – 7%.

A more recent study based on birth certificate data in California reported only 2.9% of people labor after two cesareans. (Dombrowski, 2020) That study found that teaching hospitals with higher level NICUs, lower malpractice insurance premiums, and midwives who attend births were more likely to support labor after two cesareans. 

Unfortunately, access to VBA2C depends on geography. The percentage of people who labor after two cesareans and have a VBA2C varies dramatically in the medical literature from 9% – 69% and 45% – 89% respectively. (Tahseen, 2010) Such a massive range is indicative of unequal access to care including hospitals that ban VBAC or do not offer midwifery care.

The ability to plan a VBA2C depends on the providers in the community and their willingness to practice evidence based care. If there are no local options, then VBA2C access depends on the birthing family’s ability to travel to obtain care. As we know, resource driven access disproportionally limits the care poor people and BIPOC receive.

People can decline a repeat cesarean

One of the reasons why so few people labor after two cesareans is because their provider first suggests, and then pressures them, to schedule a third cesarean. They never have the opportunity to labor.

As a reader shared with us: 

“When I was going for my VBA2C I got to my 36 week appointment only to be forced to sign the consent form for c-section at 39 weeks because ‘No one at this hospital will support you to have a vaginal birth after two cesareans.’ Well, I just had a successful, unmedicated VBA4C at the very same hospital! They may not have ‘supported’ it but as the birthing mother, I have rights. I am so glad I fought for it. It was the most healing and empowering birth.” 

OB-GYNs cannot predict the future. As a result, they cannot ethically force people into a specific decision.

There’s a lot here. First, this woman wasn’t given a choice, but there’s something more. This notion that “no one will support her.” What about respecting her right to decline surgery? No support is required. Just providers with integrity and the willingness to respect a birthing person’s right to decline any intervention, and specifically, cesarean. That is based on global human rights law and ethics opinions straight from ACOG. While they have maintained this truth for years, their 2016 committee opinion “Refusal of Medically Recommended Treatment During Pregnancy” is crystal clear: 

“The use of coercion is not only ethically impermissible but also medically inadvisable because of the realities of prognostic uncertainty and the limitations of medical knowledge. As such, it is never acceptable for obstetrician–gynecologists to attempt to influence patients toward a clinical decision using coercion.”

In other words, OB-GYNs cannot predict the future. As a result, they cannot ethically force people into a specific decision. This ethical stance does not disappear once someone has a cesarean. It doesn’t matter what hospital policy says. It doesn’t matter if there is a formal VBAC ban which “requires” repeat cesareans. Coercion has no place in obstetrics and everyone has the right to decline a cesarean.

Home birth after two cesareans (HBA2C) is sometimes the only option

Due to the fact that it can be exceedingly difficult for people to have a VBA2C in a hospital, some find that the only way for them to avoid a cesarean birth is to plan a home or birth center birth with a community midwife. 

As a reader shared: “VBA2C is absolutely an option and possible! I had to jump through hoops to find a supportive provider with my first attempted VBAC turned CBAC [cesarean birth after cesarean] after much fear mongering! I had a successful VBA2C at home 5 months ago! It was amazing and healing!”

There are many factors that impact the safety of home and birth center birth including the quality of collaboration between community providers and hospitals.

Data on home birth after two cesareans is very limited, so the risks are unknown. There are many factors that impact the safety of home and birth center birth including the quality of collaboration between community providers and hospitals. In general, studies on home VBAC have found higher VBAC rates than those typically seen in hospitals, upwards of 87%. (Cheyney, 2014) 

However, access to home birth varies greatly due to laws, rules, and common practice driven by physician groups in many places that prohibit midwives from attending VBACs either inside of a hospital, in the home, or in birth centers. These policies decrease VBAC access and increase the number of cesareans. Restrictions on midwifery options coupled with some patients’ distrust of hospital-based providers increases the incidence of unattended births (births that take place intentionally without the presence of a medical or midwifery professional, typically at home).

VBA2C is not a selfish choice

Per national guidelines, planning a labor after two cesareans is a reasonable, mainstream, and evidence based option. For all the reasons we discussed however, access remains a challenge. 

Especially for those who have a prior vaginal delivery, had their cesarean for breech, or want more children, VBA2C “plays an important role in reducing repeat cesarean delivery and associated maternal morbidities.” (Dombrowski 2020) If someone wants to plan a VBA2C, then they should have that opportunity now, rather than after three or four cesareans when the overall risks are higher; every surgical birth increases the risk that birthing people ultimately pay with their own bodies. Let’s ensure that people have equal access to birthing options when their risks are lowest. 

Are you a perinatal professional who wants to learn more about this topic? We dive into all the details in our continuing education training, “The Truth About VBA2C: Risk, Rates, & Outcomes” (approved for 2.4 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

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