Oral Misoprostol for Labor Augmentation

Abstract

To estimate the efficacy of oral misoprostol for labor augmentation. We performed a randomized, controlled trial comparing intravenous oxytocin to a 75-microgram dose of oral misoprostol. Women in spontaneous labor were eligible if they had cervical dilation of 4-8 cm and required labor augmentation. Primary outcome was the incidence of uterine tachysystole, hypertonus, or both. Secondary outcomes included labor durations, presence of nonreassuring fetal heart rate, mode of delivery, and select maternal and neonatal outcomes. Three hundred fifty women were randomized, 176 (50%) to oral misoprostol and 174 (50%) to intravenous oxytocin. Whereas the admission to study drug interval was significantly shorter in women randomized to misoprostol (median 330 minutes [252, 408] compared with 402 minutes [330, 492]; P<.001), there was no difference in the time interval between initiation of augmentation and delivery: 306 (150, 534) minutes in the misoprostol group compared with 276 (162, 462) in the oxytocin group (P=.29). Women in the misoprostol group were more likely to experience uterine tachysystole, hypertonus, or tachysystole and hypertonus compared with those in the oxytocin group (76% compared with 64%, respectively; P=.02). This increase was secondary to uterine hypertonus as the incidence of tachysystole did not differ between groups (P=.74). Women in the misoprostol arm were no more likely to experience a nonreassuring fetal heart rate (P=.20) or require a cesarean delivery for this indication (P=.78). There were no significant differences in maternal or neonatal outcomes. Oral misoprostol is an effective agent for augmentation of labor. : ClinicalTrials.gov, www.clinicaltrials.gov, NCT00906347. I.