A VBAC (pronounced “vee-back”) is a vaginal birth after cesarean, meaning you deliver a baby vaginally after having had a C-section in a previous pregnancy. About 70% of people in the U.S. who attempt one are successful. It’s a common option for those who want to avoid repeat surgery, and for many, it carries fewer risks than another cesarean.
You’ll sometimes hear the term TOLAC, which stands for “trial of labor after cesarean.” TOLAC is the process of going into labor with the goal of a vaginal delivery. VBAC is the outcome, the successful result of that trial. If the trial doesn’t lead to a vaginal birth, it ends in another C-section.
Why People Choose a VBAC
A successful VBAC avoids major abdominal surgery, which means a shorter recovery, less blood loss, and a lower risk of infection compared to a repeat cesarean. Most people who deliver vaginally go home sooner and return to normal activity faster. There’s no surgical wound to manage, and the physical limitations that follow abdominal surgery (lifting restrictions, driving restrictions, pain at the incision site) don’t apply.
The benefits also extend to future pregnancies. Each cesarean adds scar tissue to the uterus, which increases the risk of complications like abnormal placenta placement in later pregnancies. Choosing a VBAC when it’s safe can reduce those cumulative surgical risks, especially if you’re planning to have more children.
Who Is a Good Candidate
The single most important factor is the type of incision made on your uterus during your previous C-section. A low transverse incision, a horizontal cut across the lower, thinner part of the uterus, carries the lowest risk of rupture and is the most common type. If you had a high vertical (or “classical”) incision, an up-and-down cut in the upper part of the uterus, a VBAC is generally not recommended because the rupture risk is significantly higher.
It’s worth noting that the scar on your skin doesn’t always match the scar on your uterus. Your medical records from the previous surgery are the only reliable way to confirm the incision type.
Beyond the incision, several other factors affect your chances of success. Research has identified five key predictors:
- Previous vaginal delivery. Having delivered vaginally before (either before or after your cesarean) is the single strongest predictor of success, nearly tripling the odds.
- Reason for the first cesarean. If your original C-section was for a non-recurring reason, like a breech baby, your chances are better than if it was for something that could happen again, like labor that stalled.
- Age under 35. Younger maternal age is associated with roughly double the odds of success.
- BMI under 30. A lower body mass index modestly improves the likelihood of a vaginal delivery.
- Cervical readiness at admission. How dilated and thinned your cervix is when you arrive at the hospital matters. A more favorable cervix signals that your body is progressing toward delivery on its own.
When researchers scored these factors together, women with the highest scores had success rates above 85%, while those with the lowest scores fell below 50%. Your provider can help you weigh these factors together rather than looking at any one in isolation.
The Main Risk: Uterine Rupture
The most serious concern with a VBAC is that the scar from your previous cesarean could open during labor. This is called uterine rupture, and while rare, it’s a medical emergency that can harm both you and the baby.
The numbers are reassuring for most candidates. In large studies, the rupture rate during a trial of labor ranges from about 0.2% to 0.7%, compared to roughly 0.03% for a planned repeat cesarean. That means for every 1,000 women attempting a VBAC, somewhere between 2 and 7 experience a rupture. The vast majority do not.
Certain situations raise the risk considerably. Using prostaglandin medications to ripen the cervix and induce labor increases rupture rates to about 2.5%, roughly five times higher than with spontaneous labor. Because of this, prostaglandin induction is strongly discouraged during a TOLAC. Other methods of induction carry a smaller increase in risk, but your provider will weigh the options carefully.
Timing between pregnancies also matters. Deliveries spaced less than 18 months apart are associated with a higher chance of rupture, likely because the uterine scar hasn’t had enough time to fully heal.
What to Expect During Labor
A VBAC labor looks much like any other vaginal delivery, with one key difference: closer monitoring. Because of the small risk of rupture, your care team will watch you and the baby more carefully throughout labor. Continuous fetal heart rate monitoring is standard, since changes in the baby’s heart rate can be an early sign that the scar is under stress.
You can typically receive an epidural during a TOLAC. There’s a common misconception that pain medication would mask the signs of rupture, but fetal monitoring is the primary detection tool, not your pain levels.
If labor progresses well, the delivery itself is no different from a first-time vaginal birth. If complications arise or labor stalls, the team will move to a cesarean. This is why facility matters: hospitals that offer VBACs need to have surgical teams and an operating room available quickly. Not every hospital or birth center meets this requirement, so it’s worth confirming early in your pregnancy that your delivery location supports TOLAC.
When a VBAC Is Not Recommended
Some situations make the risks too high. A VBAC is typically ruled out if you have a high vertical uterine scar, a history of uterine rupture in a prior pregnancy, or certain other uterine surgeries that have weakened the wall of the uterus. Having had three or more prior cesareans may also shift the risk-benefit balance, though this is assessed on a case-by-case basis.
If a VBAC isn’t a safe option for you, a planned repeat cesarean can be scheduled around 39 weeks. This is a different experience from an emergency cesarean during labor. It’s a controlled procedure with predictable recovery, and for some people, it’s the right choice even when a VBAC is technically possible. The decision is personal, and the best outcome depends on your specific medical history, your pregnancy, and what matters most to you.