Sublingual versus vaginal misoprostol for induction of labor at term: a randomized prospective placebo-controlled study.

AIMS: To assess the effectiveness and safety of sublingual misoprostol (50 microg), compared with the same dose administered vaginally every 6 h for cervical ripening and labor induction in women with a viable fetus in the third trimester of pregnancy.

METHODS: This double-blind randomized prospective placebo-controlled trial included 480 women with medical or obstetric indications for labor induction and undilated, uneffaced cervices. The patients were assigned randomly to receive 50 microg of sublingual or 50 microg of vaginal misoprostol every 6 h for 24 h. Maternal and neonatal outcome were analyzed.

RESULTS: A total of 169 (70.4%) patients delivered vaginally in the sublingual group compared to 160 (66.7%) in the vaginal group. The main indications for cesarean section in both groups were fetal distress (33/71 [46.4%] vs 38/80 [47.5%]), followed by failure of labor progress. Thirty three (13.8%) patients in the sublingual group had meconium staining of the amniotic fluid compared to 39 (16.3%) in the vaginal group. There was no difference between the groups regarding the induction-to-delivery interval, duration of labor, neonatal outcome or maternal side-effects.

CONCLUSION: Sublingual misoprostol is as effective as vaginal misoprostol for induction of labor at term. Moreover, the sublingual route is associated with a significantly higher patient satisfaction rate than vaginal misoprostol.