What to Know About VBAC

It used to be a given: Women who had a baby by cesarean section would deliver by C-section with any following pregnancy. That’s not the case anymore.

Vaginal birth is now an option for many expectant mothers with a prior C-section. In fact, VBAC — rather than a repeat C-section — is recommended when possible, depending on individual circumstances of the pregnancy, mother and baby. If you’re considering VBAC, here’s what maternal-fetal health experts want you to know.

What Is VBAC/TOLAC?

Although the terms VBAC and TOLAC are often used interchangeably, there is a difference as defined by the American College of Obstetricians and Gynecologists:

TOLAC (trial of labor after cesarean delivery). This is a planned attempt to deliver vaginally by a woman who has had a previous cesarean delivery, regardless of outcome. (In some cases, TOLAC fails and women need a repeat C-section after all.)

VBAC (vaginal birth after cesarean delivery). When TOLAC succeeds it becomes VBAC — a vaginal birth after cesarean delivery.

According to ACOG, delivery by VBAC may help avoid health problems linked to multiple C-sections for women who want to have more children. Reducing the risk of bowel or bladder injury, as well as hysterectomy and placenta problems in future pregnancies — problems associated with multiple C-sections — are reasons for some women to consider VBAC/TOLAC.

[ See: 11 Things Your OB-GYN Wants You to Know. ]

Reasons for a C-Section

“There are a lot of different reasons women have cesarean deliveries,” says Dr. Katherine Economy, a maternal-fetal medicine specialist with Brigham and Women’s Hospital and an assistant professor of obstetrics, gynecology and reproductive biology at Harvard Medical School in Boston. “Some are for unavoidable obstetric indications: The baby is breech, the bottom is down and it’s recommended that they have a cesarean delivery for the safety of the baby.”

In other cases, concerns can arise after a woman enters into labor. “Either the baby is too large for the pelvis, or there isn’t enough contraction power or sometimes babies just don’t tolerate labor, and so women have a C-section during labor,” Economy says.

Sometimes, women just opt for a C-section. “We call it cesarean delivery by maternal request,” Economy says. “There are women who just choose to have a cesarean delivery in the first place.” However, she adds, “Some women may really feel like they want the opportunity to try to have a vaginal birth afterward.”

Why VBAC?

Different motivations can enter into an expectant mother’s decision to attempt a vaginal delivery instead of planning another C-section.

“There are a couple reasons to consider undergoing a trial of labor to have a VBAC,” says Dr. Julia Cormano, an OB-GYN and assistant professor of obstetrics, gynecology and reproductive sciences with UC San Diego Health System. “The first is that with a repeat C-section and each subsequent C-section, risks go up to maternal health. It’s a big operation — a major abdominal surgery. So, when you compare a major abdominal surgery with a successful vaginal delivery, the risk of death is slightly higher for the mom (with the surgery).”

The need for blood transfusions and risk of infections are slightly higher with major abdominal surgery than vaginal delivery, Cormano says. “And certainly, the risks in future pregnancies start to go up significantly,” she says. Recovery period is typically longer for women who have C-sections compared to VBAC.

Women need to discuss their wishes and preferences with doctors in the shared decision-making process. “Part of counseling when a woman comes to me is to try to understand: What is her life plan?” Cormano says. “Does she want five kids? She’s had prior C-sections and she’s looking forward at her family size. The larger family size that’s desired, the more important it might be to try for a VBAC to reduce those risks.”

It’s also an emotional choice and major life event. “Birth is very different from other medical sorts of experiences,” Economy says. “There’s nothing like it, really.” People don’t come into their hernia repair, cancer treatment, heart transplant or kidney dialysis with the same mindset, she notes. “Birth, of course, is weighted with centuries of human emotion and that’s important to acknowledge.”

Perspectives on type of delivery vary among expectant mothers. “Some women very much feel that having the opportunity to labor and having that vaginal birth is a part of the narrative that they want for their pregnancy,” Economy says. “Other women are not as attached to that narrative.”

Vaginal Delivery and Babies

C-sections are primarily done for safe delivery of the baby, Cormano says. “The trial of labor in general is a higher-risk event for the baby in an effort to get a safer outcome for the mom,” she adds. “Somebody who’s being guided toward a repeat C-section is probably being guided there with the hope of minimizing risk to the baby, because the baby’s the one who’s at most risk in the situation of uterine rupture.” (This can be a TOLAC complication.)

However, vaginal birth may offer health advantages to the newborn as well as the mother. “Babies that are born by C-section often require a little extra transitioning time, because they don’t have the squeezing process they go through in the birth canal, where the fluid gets pushed out of their lungs,” Economy says. “So that’s one benefit if you have a vaginal delivery.”

Cutting-edge research is now being done to evaluate the advantage of the baby being exposed to the mother’s vaginal microbiome during birth, Cormano notes. This normal bacteria may help form the baby’s immune system in later life and play a role in future health outcomes.

“We do know there are certain things that are advantageous to a baby going through vaginal delivery,” Cormano says. “They seem to have a slightly lower rate of respiratory distress and it kind of helps them go through the wringer, so to speak, of that vaginal delivery.”

[ Read: Pregnancy and Prenatal Tips ]

VBACs Slowly Rising

International medical specialty groups, including ACOG, have developed expert recommendations regarding VBAC as an alternative for women who’ve had previous C-sections.

In the U.S., VBAC rates increased from 2016 (12.4%) to 2018 (13.3%), according to a March 2020 data brief from the National Center for Health Statistics, part of the Centers for Disease Control and Prevention. However, the overall increase fell short of the Healthy People 2020 maternal, infant and child health objective of increasing VBAC rates to slightly above 18% nationwide.

VBAC Success Factors

VBAC may be more likely to succeed for some women.

A predictor of success is if they’ve already had a vaginal delivery. “A woman who has had prior successful vaginal deliveries, and then for whatever reasons had a C-section and has had enough time for that C-section to heal — we like to see at least a year and half before getting pregnant again — is a really good candidate,” Cormano says. “Her body knows how to do this and has shown that a baby can fit through her pelvis. Especially if she goes to term, has a normal-size baby and had good recovery time, she has a high chance of successful delivery.”

An analysis for estimating the chance of a vaginal birth after cesarean delivery, published in the December 2021 American Journal of Obstetrics and Gynecology, included registry data on more than 11,500 women who had delivered a single baby at 37 weeks or more, had a previous C-section with a horizontal incision and had a TOLAC.

Of these women, nearly 75% experienced VBAC, and researchers found these significant variables:

— Women who were taller and had a previous vaginal birth, particularly if that had occurred after a previous C-section, were more likely to have VBAC.

— Older women, heavier women, those whose previous C-section was related to delivery problems with dilation or fetal descent, or who were treated with medication for chronic hypertension, were less likely to have VBAC.

In some cases, VBAC may be possible even after two previous C-sections. However, the risk for uterine rupture increases. If both of the mother’s C-sections were for failed labor, for instance, in which the baby didn’t descend to the pelvis either time, “the chances for her having a successful vaginal delivery really are much, much lower,” Cormano says. “So that risk-benefit decision-making changes and that might be somebody who is better guided toward a repeat C-section.”

What Are VBAC Risks?

Because VBAC/TOLAC comes with risks of its own, careful consideration goes into recommending and choosing between vaginal delivery and another C-section. The most serious risk involves separation of the surgical scar that resulted from the mother’s previous C-section.

“When there’s a scar on the uterus, there is some increased risk for the scar opening during labor,” Economy says. Although the phrase “uterine rupture” is commonly used for this event, she tries to avoid that terminology when referring to surgical scar separation.

“That imagery can be very upsetting,” Economy says. “In counseling women, I really try to reflect more that sometimes the scar opens. Frankly, the scar can open and women can be totally asymptomatic. Or, the scar can open and it can be quite dramatic. There can be bleeding and both the mother and the baby’s life can be at risk in that situation. Those are rare events, but women need to hear about it. They need to make the decision with all the available information.”

The type of uterine scar a woman has can contribute to having a higher risk of rupture during VBAC. “For instance, if a woman has an up-and-down scar on her uterus, we really discourage labor, because the uterine rupture or scar separation rate is much higher,” Economy explains.

With induced labor, medications or other methods are used to stimulate contractions instead of waiting for labor to begin on its own. With TOLAC, induced labor slightly raises the risk of scar separation, Economy says. “So we prefer women to go into spontaneous labor,” she says. “Their chance of success is higher, their risk of uterine rupture is lower.”

[ See: Questions Doctors Wish Their Patients Would Ask. ]

Not Always the Right Choice

With all the health and safety considerations involved, and the need to understand and carefully weigh risks and benefits, it’s essential for women to receive counseling from their maternal health providers before deciding whether to move forward with VBAC.

Considering such factors in the context of a woman’s obstetric history, overall health and personal preferences helps expectant parents arrive at an informed decision regarding delivery. “For women who have a prior cesarean delivery, it requires a more balanced and nuanced conversation,” Economy says. “I always need to hear from them: What’s the thing that you most value in this process? Understanding, of course, that everybody wants to be healthy and have their baby be healthy. That’s a foregone conclusion.”

VBAC is riskier under certain other circumstances. “There’s a lot of gray area there, so counseling is super-important,” Cormano says. “It may not be a hard-and-fast ‘no, don’t do this,’ but where the risks start to add up.” These are some situations were VBAC/TOLAC may be discouraged or contraindicated:

Several previous C-sections. “We consider a history of more than two C-sections to be pretty much a contraindication,” Cormano says. “The risk now is probably too high.”

Twins, triplets or more. Whether someone is having multiple babies is another factor, Cormano says. Along those lines, a baby’s size can matter: “Is this a very big baby?”

Timing issues. “Was there enough time in between the last C-section and laboring for recovery?” is another factor, Cormano says.

Placenta previa. If the placenta is partially or completely covering the mother’s cervix, or placenta previa, vaginal delivery is not recommended, Cormano says.

Breech position. “At most hospitals now, we don’t recommend vaginal delivery if the fetus is malpresenting,” Cormano says, “if the baby is breech, or feet first, for example.”

A lengthy list exists of reasons to be guided away from vaginal delivery after C-section, Cormano points out, making individual counseling essential.

Safe Environment

The facility where the woman intends to go for maternity care is another key factor in the VBAC choice. Because a VBAC attempt could necessitate a C-section, and with the low but real risk of a scar separation emergency, it’s imperative for mothers to be in an environment that can promptly respond, around the clock, in any delivery scenario that arises, with anesthesiologists, the blood bank and the neonatal intensive care unit available 24/7.

“In our institution, women who are undergoing TOLAC have to be continuously monitored,” Economy says. “So you have to have monitors on the baby and monitors on the uterus all the time.”

Not every maternity facility allows VBAC as a choice. “They won’t offer TOLAC because they have obstetricians who take call at home, (so) they don’t have a provider immediately available,” Economy says. “Women who are considering this option need to do their research and pick a hospital that’s very comfortable and experienced with offering TOLAC.”

That brings up a cautionary note: “Occasionally, because patients have had experiences where they’ve been told no on VBAC, sometimes people choose to do that at home,” Cormano says. “And I would just urge people not to do that. We’ve seen really tragic and preventable outcomes and it’s sadly often because they’ve been told no or there’s a distrust of the medical system.”

By going to the right place, mothers are supported for vaginal delivery after C-section, when it’s indicated. Starting in December, you can look through the newly launched U.S. News Maternity Care ratings to find high-performing maternity care near you. These ratings highlight key factors of care for uncomplicated pregnancies. If yours is a complicated or high-risk pregnancy requiring more intensive care, see the Best Hospitals for Neonatology rankings for care of a high-risk newborn.

More from U.S. News

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What to Know About VBAC originally appeared on usnews.com

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