Maternal and neonatal outcome of labour induction at term comparing two regimens of misoprostol.

AIM To compare the efficacy and safety of two misoprostol dosing regimens for induction of labour in primiparous (1P) and multiparous (>1P) women. METHODS Retrospective study of induction of labour using vaginal misoprostol 25 μg vs. 50 μg every 6 h in 942 women at a tertiary centre. The main outcome variables are induction-to-delivery interval, latency period duration, vaginal delivery within 24 h, and maternal and foetal safety outcome. RESULTS With the 50 μg regimen, induction-to-delivery intervals were significantly shorter: 18.4 h vs. 24.6 h (1P) and 14 h vs. 17.9 h (>1P), as was latency period duration (by 5.4 and 4 h, respectively). Vaginal delivery within 24 h was significantly more frequent, as were non-reassuring foetal heart rate (1P: 20% vs. 14%) and tachysystole (1P: 31% vs. 11%; >1P: 21% vs. 7%). No uterine rupture was reported. Neonatal outcomes were similar except for significantly more frequent infant referral to neonatal intensive care in the >1P group receiving the 50 μg regimen (11% vs. 4%). CONCLUSION Vaginal misoprostol 25 μg seems to maintain efficacy with more acceptable maternal and neonatal safety. As induction of labour is an off-label use for misoprostol, safety should be prioritised with the lower dosage regimen despite the longer induction-to-delivery interval.