Vaginal misoprostol for induction of labor: a randomized controlled trial

To evaluate the effectiveness and safety of the vaginal application of misoprostol for induction of labor at term, with the interval duration from labor induction to vaginal birth as the primary outcome measure.

Two hundred twenty-two women with indications for induction of labor at term were randomized to receive either misoprostol 50 micrograms per vagina every 4 hours as needed or our standard approach (physician-chosen combinations of intracervical or vaginal dinoprostone every 6 hours, artificial rupture of membranes, and oxytocin infusion).

Mean (+/-standard deviation) time to vaginal delivery was 753 +/- 588 minutes for misoprostol versus 941 +/- 506 minutes for the physician-chosen combination (P = .018). Oxytocin infusion was used less frequently (relative risk [RR] 0.48, 95% confidence interval [CI] 0.31-0.74). There was no significant difference in cesarean rate or maternal morbidity. Neonatal outcomes, including cord-blood acid-base analysis, were not significantly different. The estimated cost per patient in Canadian dollars for prostaglandins was $0.22 with misoprostol and $70.00 with standard therapy.

Vaginal misoprostol is a cost-effective alternative to current labor-induction protocols. We found no evidence of harm to mother or newborn in substantive outcomes.