What Affects VBAC Success

Pregnancy, labor, and delivery are different for every woman and difficult to predict. Even if your first pregnancy required a cesarean, the next one may not. The likelihood of a successful vaginal birth after cesarean (VBAC) is influenced by various factors. Usually a combination of factors affects how well or poorly a trial of labor goes.

Your chances of a successful VBAC are best when:¹

• Your previous cesarean was not done for stalled labor.
• You do not have the same condition that led to a previous cesarean (such as a breech, or feet-down, fetus).
• You have had a vaginal delivery or a successful VBAC before.
• Your labor starts on its own, and your cervixdilates well.
• You are younger than 35.²

Your chances of a successful VBAC are lower when:¹

• Your previous cesarean was because of difficult labor, which is called dystocia. This is especially true if you were fully dilated when you had a cesarean section for dystocia.
• You are obese.
• You are older than 35.²
• Your fetus is very large [estimated as bigger than 9 lb (4082 g)].
• You are beyond 40 weeks of pregnancy.