Topic Overview

When labour does not start on its own and delivery needs to happen soon, contractions can be started (induced) with medicine. Some doctors avoid inducing labour when a woman is trying vaginal birth after caesarean (VBAC). But others are okay with the careful use of certain medicines to start labour or strengthen contractions.

For a woman who has a caesarean scar on her uterus, there is a chance the scar can break open during labour. This is called uterine rupture. Medicines used to induce labour may increase the risk of uterine rupture.

When a VBAC labour has not started on its own, certain medicines, such as oxytocin, may be carefully used to help start labour. Oxytocin may also be used to get a slow labour going again. Oxytocin is less likely than the medicine misoprostol to increase the risk of uterine rupture. Misoprostol is not recommended for use in VBAC.footnote 1

In one large study, uterine rupture occurred in:footnote 1

  • About 14 out of 1,000 women who were induced with misoprostol.
  • About 11 out of 1,000 women who were induced with oxytocin.
  • About 4 out of 1,000 women who had a spontaneous labour.

Inducing labour in a woman trying a VBAC may also increase the chance of needing a C-section. Women who try to have a VBAC may be more likely to have a successful vaginal birth if labour is allowed to start on its own (spontaneous labour).footnote 1



  1. American College of Obstetricians and Gynecologists (2010). Vaginal birth after previous cesarean delivery. ACOG Practice Bulletin No. 115. Obstetrics and Gynecology, 116(2): 450–463.


ByHealthwise Staff
Primary Medical Reviewer Sarah Marshall, MD - Family Medicine
Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer Femi Olatunbosun, MB, FRCSC - Obstetrics and Gynecology

Current as ofMay 22, 2015