Objective: To analyze published randomized trials assessing the safety and efficacy of misoprostol for cervical ripening and labor induction.
Data sources: We supplemented a search of entries in electronic data bases with references cited in original studies and review articles to identify randomized trials of misoprostol for cervical ripening and labor induction.
Methods of study selection: Two blinded investigators performed independent trial quality evaluation and data abstraction of randomized clinical trials assessing the efficacy of misoprostol as a cervical ripening and labor-inducing agent.
Tabulation, integration, and results: We calculated an estimate of the odds ratio (OR) and risk difference for dichotomous outcomes, using both a random- and fixed-effects model. Continuous outcomes were pooled using a variance-weighted average of the within-study difference in means. Of 16 studies identified, eight met our criteria for meta-analysis. These eight trials included 966 patients (488 received misoprostol and 478 were controls). Women who received misoprostol for cervical ripening and labor induction had a significantly lower overall cesarean rate (OR 0.67, 95% confidence interval [CI] 0.48, 0.93) and a higher incidence of vaginal delivery within 24 hours of misoprostol application (OR 2.64, 95% CI 1.87, 3.71). Use of misoprostol was associated with a higher incidence of tachysystole (OR 2.70, 95% CI 1.80, 4.04) but not hyperstimulation (OR 1.91, 95% CI 0.98, 3.73). The incidences of abnormal 5-minute Apgar scores and admissions to the neonatal intensive care unit were similar in the misoprostol and control groups. The pooled estimate of the mean interval from start of induction to delivery was 4.6 hours fewer (95% CI -3.5, -5.7) in the misoprostol group.
Conclusion: Published data confirm the safety and efficacy of intravaginal misoprostol as an agent for cervical ripening and labor induction.