Oral misoprostol (100 mu g) versus vaginal misoprostol (25 mu g) in term labor induction: a randomized comparison

Objective. To compare the efficacy of vaginal misoprostol (25 mug) to oral misoprostol (100 mug) in labor induction at term.

Methods. One hundred and one women at term, with indications for labor induction and cervical Bishop's scores of less than 8, were randomly assigned to receive 100 mug of oral misoprostol or 25 mug vaginal misoprostol after random allocation. This could be repeated every 4 h to a maximum of five doses. The number delivering vaginally within 24 h of the induction was the main outcome measure.

Results. Of those who delivered vaginally (74.5% in the oral group vs. 72% in the vaginal group), significantly fewer women delivered within 24 h of induction in the oral group (42.1% vs. 72.2%, RR 0.6, 95% CI 0.4-0.9), with more women receiving more than one dose (45.7% vs. 16.7%, RR 2.7, 95% CI 1.2-6.0). More women in the oral group received oxytocin (68.6% vs. 44%, RR 1.6, 95% CI 1.1-2.2), and the induction to delivery interval was shorter in the vaginal group, although this was not statistically significant [28.9 h (SD 20.2) vs. 20.6 h (SD 16.1), mean difference-8.3 h, 95% CI-16.8 to 0.2]. There were no differences in the modes of delivery, uterine hyperstimulation rates or in the neonatal outcomes.

Conclusion. Vaginal misoprostol in its currently recommended dose of 25 mug seems to be more efficacious than the 100 mug oral dose.