Sublingual versus Vaginal Misoprostol for the Induction of Labor at Term: A Randomized, Triple-Blind, Placebo-Controlled Clinical Trial

Background: We sought to compare the effectiveness and safety of sublingual versus vaginal misoprostol for the termination of pregnancy with a live full-term fetus.Methods: This randomized, triple-blind, placebo-controlled clinical trial was performed on 200 primiparous women with normal, singleton, full-term pregnancies candidated for the induction of labor. Sublingual and vaginal tablets containing misoprostol (25 mcg) or placebo in similar shapes were administered every 4 hours until the Bishop score reached above 8. Maternal and neonatal complications and outcomes were compared.Results: There were 100 parturient women in each group. The mean maternal age, gestational age, and Bishop score at the commencement of misoprostol had no statistical differences between the sublingual and vaginal groups. The mean time interval between misoprostol commencement and delivery was 497.10±291.49 and 511.67±08.46 minutes for the sublingual and vaginal groups, correspondingly. Twenty-two women had Cesarean deliveries in the sublingual group versus 14 in the vaginal group. Meconium-stained amniotic fluid was seen in 12 women in the sublingual group and 4 in the vaginal group (P=0.03). Late fetal heart rate deceleration was observed in 8 women in the sublingual group and 4 in the vaginal group (P=0.22). The mean neonatal birth weight, blood gas value at birth, Apgar score, and length of admission time in the neonatal intensive care unit were not different between the 2 groups.Conclusion: Sublingual and vaginal misoprostol had similar effectiveness; however, meconium-stained liquor was observed considerably more frequently with sublingual misoprostol than with vaginal misoprostol.Trial Registration Number: IRCT201402096541N3