A comparison of orally administered misoprostol to intravenous oxytocin for labor induction in women with favorable cervical examinations

Objective The purpose of this study was to compare orally administered misoprostol with intravenous oxytocin infusion for labor induction in women with favorable cervical examinations (defined as a Bishop score of 6 or more). Study design One hundred ninety-eight women with indications for labor induction and favorable cervical examinations were assigned randomly to receive oral misoprostol or oxytocin induction. Misoprostol, 100 mg, was administered every 4 hours up to 6 doses, or intravenous oxytocin was administered by standardized protocol. Results One hundred ten (55.6%) women received misoprostol; 88 (44.4%) received intravenous oxytocin. There was no statistically significant difference in the average interval from start of induction to vaginal delivery, being longer in the misoprostol group (789.4 ± 510.2 minutes) than in the oxytocin group (654.0 ± 338.2 minutes, P=.19, log-transformed data). Two women had tachysystole develop in each treatment group. More women in the misoprostol group experienced hyperstimulation (7/110, 6.4%) than in the oxytocin group (0/88, P=.02, Fisher exact test). Nine (8.1%) misoprostol-treated women and 8 (9.1%) oxytocin-treated women underwent cesarean deliveries (P=.82). There was a presumed uterine rupture in a misoprostol-treated multipara women. There were no statistically significant differences in neonatal outcomes between the groups. Conclusion Oral misoprostol offers no benefit over intravenous oxytocin for labor induction in women with favorable cervical examinations. It is associated with a higher likelihood of uterine hyperstimulation and may increase the risk of uterine rupture.