A comparison of 100 μg oral misoprostol every 3 hours and 6 hours for labor induction:: A randomized controlled trial

Objective: To compare the efficacy and safety of 100 mug oral misoprostol for induction of labor between the regimen of 3 hour and 6 hour interval administration. Methods: Singleton pregnancies indicated for induction of labor between 34 and 42 weeks of gestation in the condition of unfavorable cervix (Bishop score less than or equal to4) and no contraindication for prostaglandins therapy were recruited into the study. All pregnant women were randomly assigned to receive 100 mug oral misoprostol every 3 hours or 6 hours until the cervix was favorable for amniotomy, spontaneous rupture of membranes or active labor occurred. Results: The mean time interval from induction to vaginal delivery was significantly shorter in the 3 hour interval group, compared with the 6 hour interval group (13.82 +/- 6.98h and 17.66 +/- 7.48 h, P = 0.0019). There was no significant difference between the groups with regard to mode of delivery, analgesic requirement, maternal complication and neonatal outcome. Conclusions: 100 mug oral misoprostol every 3 hours is more effective for labor induction than every 6 hours but there was no difference in mode of delivery, analgesic requirement, maternal complications and neonatal outcome. A dose of 100 mug misoprostol orally every 3 hours seems to be the optimum regimen and the new option for labor induction. However, further study should be performed.