Mifepristone with Misoprostol versus Misoprostol Alone for Induction of Labor in Postdated Pregnancy- A Comparative Study

Abstract

Introduction: Postdated pregnancy is associated with increased maternal and neonatal complications, often necessitating induction of labour. Mifepristone, an antiprogesterone agent, facilitates cervical ripening and may enhance the effectiveness of misoprostol.

Aims: To compare the efficacy and safety of mifepristone combined with misoprostol versus misoprostol alone for induction of labour in postdated primigravida.

Methods: This cross-sectional comparative study was conducted at Nepalgunj Medical College from April 2025 to April 2026. A total of 122 primigravida with Bishop score <6 were enrolled and randomly allocated into two groups. Group A received oral mifepristone (200 mg) followed by vaginal misoprostol (25 mcg), while Group B received vaginal misoprostol alone. Outcomes assessed included Bishop score improvement, induction-to-delivery interval, mode of delivery, and neonatal outcomes. Statistical analysis was performed using the Chi-square test, with p<0.05 considered significant.

Results: The mean Bishop score at reassessment was significantly higher in Group A (4.69±0.74) compared to Group B (3.41±1.21; p<0.001). The induction-to-delivery interval was significantly shorter in Group A (610.16±102.62 minutes) than in Group B (1151.15±133.31 minutes; p<0.001). Vaginal delivery rates were higher in Group A (59.01%) compared to Group B (40.98%; p=0.046), while cesarean section rates were lower in Group A (34.42% vs. 55.73%; p=0.045). Neonatal outcomes, including APGAR scores and NICU admissions, were comparable between groups.

Conclusion: The combination of mifepristone and misoprostol is more effective than misoprostol alone for induction of labour in  postdated primigravida, with improved cervical ripening and higher vaginal delivery rates without increasing neonatal risk.