VBAC Basics


What is VBAC?

VBAC stands for "vaginal birth after cesarean" and refers to giving birth through the vagina after a woman has already had a cesarean section (C-section). Because a C-section leaves a scar on the uterus, there are concerns about the pressure from labor causing the scar on the uterus to break (rupture).

Is planning a VBAC or a repeat C-section safer for my baby?

You may hear from some people that another C-section is safest for your baby. While it is true that the C-section scar can give way (uterine rupture) during labor, ensuring that a surgical team is readily available is an important precaution for this situation. But C-section has its own risks for both you and the baby. You need to understand the full range of risks and benefits associated with both procedures and discuss your preferences with your care provider. You've come to the right place to do just that, so keep reading!

Is planning a VBAC or a repeat C-section safer for me?

Both VBAC and repeat C-section have some increased risks for mothers. However, planned vaginal birth is safer overall for you than a planned repeat C-section unless there is a clear and well-supported need for a C-section. With supportive care, 75 or so out of 100 women who plan VBAC do give birth vaginally. The others go on to have another C-section, primarily for reasons unrelated to the scar. Keep reading to learn more about the pros and cons of both procedures and also check out the C-Section part of the website.

Is it planning a VBAC or a repeat C-section safer for me and my babies in any future pregnancies?

A VBAC in your current pregnancy is the much safer choice for any future pregnancies you may have. Each additional C-section increases the amount of internal scar tissue. Scar tissue makes it more and more difficult for the placenta that nourishes the baby to grow and attach normally. This can pose life-threatening risks to babies and mothers.

More scar tissue also increases the chance of adhesions, where nearby tissue or organs grow together. Adhesions make C-section more difficult and risky in future pregnancies.

A VBAC this time around has other advantages in future pregnancies: if you go on to have more children, you'll most likely give birth vaginally and your earlier C-section scar is unlikely to rupture.

Why do I hear conflicting information about VBAC vs. repeat C-section?

For decades, most women who had a C-section went on to plan another C-section for later pregnancies. This is because doctors were mainly concerned that the scar from the past cut in the uterus could open during labor (uterine rupture) and cause serious complications for the mother or baby. Often they did not balance this with possible risks of surgery for women and babies, in the short and longer terms.

In the 1980s and '90s, many health professionals, advocates, pregnant women, policymakers and researchers encouraged VBAC because:

  • Doctors began making the surgical cut in a different part of the uterus, which is much less likely to open during a VBAC labor.
  • More research showed VBAC to be safe.
  • As more women had C-sections, the risks of the surgery became clearer.

Then, opinions turned back toward a preference for repeat C-sections. This back-and-forth has left many women struggling to make sense of conflicting, incomplete and sometimes misleading information about the safety of VBAC vs. repeat C-section and to decide what course to choose if they have had a C-section and are again pregnant.

Today, research continues to make clear the risks and benefits of both VBAC and repeat C-section, and more women are fighting for the chance to make their own choice — so VBAC may become more available and common soon.

Why might my maternity care provider recommend a repeat C-section?

There are a number of special situations where your care provider might recommend a C-section. It's important to note that in the situations listed below, research does not support a specific need for C-section based on risk of the previous C-section scar rupturing. If you're facing any of these situations, you may have to push your doctor a bit to consider the VBAC option.

  • Your care provider doesn't know what type of uterine scar you have. Many years ago, studies showed that a side-to-side cut on the lower part of the uterus (low transverse incision) produced a much stronger scar than the previously used up-and-down (classical) incision. As a result, nearly all women who had a C-section before and are pregnant again have a side-to-side scar. To be sure what kind of scar you have, your care provider will need your medical record from your earlier C-section (the direction of the scar on your skin may not be the same as the scar on your uterus). Ultimately, research suggests that there is no increased risk for scar rupture in women when the direction of the scar is unknown, compared with women with a known low transverse scar.
  • Your previous C-section was because you had a premature (preterm) birth. In this case, the lower part of your uterus may not have developed enough when you had the C-section to allow the doctor to do a side-to-side cut, so she or he might have done an up-and-down incision at the bottom of the uterus. The limited research available shows this type of scar should be just as strong as the more common side-to-side scar.
  • Your doctor expects your baby to be larger than average. Some people believe babies that are expected to weigh more than 8 pounds, 13 ounces (4,000 grams) put extra pressure on the C-section scar, increasing risk of rupture. Research does not support this concern.
  • Your pregnancy goes beyond your due date. Studies do not show an increase in problems with the scar in pregnancies going beyond 40 weeks, although some studies show an increase if labor is induced after this point.
  • You're expecting twins. Studies have not shown an increase in problems with the scar during labor with twins, compared with one baby.
  • Your baby is in a buttocks- or feet-first (breech) position. Few providers are comfortable with vaginal birth for breech babies, even if you haven't had a C-section before. That being said, if you're interested in attempting VBAC and your baby is breech, your provider can use hand maneuvers on the belly to try to turn the baby into a head-first position (external cephalic version). There is little research on whether turning the baby could increase risk of scar rupture, but the existing research does not indicate increased risk.