Isosorbide Mononitrate versus Misoprostol for Cervical Ripening and Induction of Labour at Term

Abstract

To assess the efficacy and safety of isosorbide mononitrate (IMN) compared with misoprostol for cervical ripening and labour induction at term. In this comparative study two hundred term pregnant women with indication for induction of labour were randomly divided to receive either 40 mg IMN tablet vaginally (n=100) or 50 μg misoprostol tablet vaginally (n=100) every 6 hours interval for a maximum of 4 doses. Progress & outcome of cervical ripening, labour induction and adverse effects were assessed. Change in cervical score was higher in misoprostol group than IMN group. Time from start of medication to vaginal delivery in IMN group was significantly longer, 28.66 ± 5.283 hours, than in misoprostol group, 16.12 ± 5.581 hours. Vaginal delivery occurred in 77% in IMN group and 69% in misoprostol group. There were no tachysystole or uterine hyper stimulation in the IMN group while in misoprostol group it was 17% and 11% respectively. Maternal satisfaction was higher in IMN group. Cervical ripening is satisfactory with IMN. Though misoprostol is singly more effective than IMN but IMN with oxytocin results in more vaginal delivery. Fetal and maternal side effects are less in IMN group.