Cervical ripening with oral misoprostol at term.

OBJECTIVES: To determine the efficacy of 200 microg single dose oral misoprostol as a cervical priming agent at term.

METHODS: In this double-blind randomized trial, 156 pregnant women requiring induction of labor with gestational age of 37-42 weeks and Bishop score < or =5, were randomized to receive either 200 microg of misoprostol or a placebo, orally. Labor was induced with intravenous oxytocin infusion 12 h after oral medication if the patient did not go into labor. The primary outcome was the change in the Bishop score 12 h after oral medication. The secondary outcomes were the timings starting from the drug administration to the onset of uterine activity, interval between oral medication and delivery, oxytocin need for induction, mode of delivery, frequency of side effects, and neonatal and maternal outcome. The chi-square or Fisher exact test, Student's t-test, and Mann-Whitney U-test were used for analysis of the data.

RESULTS: There were no significant differences in maternal characteristics or indications of induction. The Bishop score 12 h after oral medication significantly improved in the misoprostol group compared with the control group [55 (70%)>8 vs. 4 (5%)>8; P<0.001]. The induction rate was significantly reduced in the misoprostol group (P<0.001). The interval between oral medication and the onset of uterine activity was significantly shorter in the misoprostol group (P<0.001). The interval between oral medication and delivery was also significantly shorter in the misoprostol group (P<0.001). The cesarean delivery rate was significantly lower in the misoprostol group (P<0.001). There were no differences between the groups with respect to the incidence of tachysystole, hyperstimulation, adverse neonatal or maternal outcome.

CONCLUSIONS: Oral administration of 200 microg single dose of misoprostol is an effective agent not only for cervical priming but also for induction of labor at term. Furthermore, it reduces the rate of cesarean deliveries.