COMPARISON OF VAGINAL ISOSORBIDE MONONITRATE PLUS VAGINAL MISOPROSTOL VERSUS MISOPROSTOL ALONE FOR INDUCTION OF LABOR IN POSTDATED PREGNANCIES

Abstract

Background: The greater the number of days after term, the greater are the risks to both mother and fetus. Induction of labour is often employed to minimize complications of extended pregnancies. Misoprostol is a well established pharmacological method for ripening and inducing labour, and the nitric oxide donor isosorbide mononitrate (IMN) has the potential to remodel the cervix without directly inducing uterine contractions. These agents may prove more effective in inducing, if combined. Objective: To compare effect of vaginal IMN plus vaginal misoprostol alone in post dated pregnancies in terms of duration between induction to delivery. Methods: This was a randomized controlled trial that was carried out at Department of Obstetrics and Gynecology, Sir Ganga Ram Hospital, Lahore from May 2025 to September 2025. 60 women with pregnancies > 40 weeks completed gestation were randomized into 2 equal groups. Group A received 40 mg of vaginal IMN and 50 μg of vaginal Misoprostol and Group B received 50 μg of vaginal Misoprostol alone. When necessary, doses were repeated every 6 hours, for four doses. The main outcome was time (in minutes) from the start of induction to delivery. SPSS version 27 was used to analyze the data. Results:  The mean induction to delivery time was significantly less in Group A than Group B (1152 ± 105 minutes vs. 1425 ± 148 minutes; p < 0.001). These reductions were found to be statistically significant in stratified analyses based on age, BMI, and parity. Conclusion: In postdated pregnancy, IMMN with misoprostol significantly shortened the induction to delivery interval (IDI) as compared to the group receiving misoprostol alone.