Comparing the Efficacy and Safety of Oral and Vaginal Isosorbide Mononitrate, With Oral Propranolol in Cervical Ripening and Labor Induction Publisher



Shirazi M ; Tajpour M ; Jafarabadi K ; Rahimi Sharbaf F ; Sahebdel B ; Golshahi F ; Saedi N ; Aslanpour M
Source: Journal of Obstetrics, Gynecology and Cancer Research Published:2026

Abstract

Background & Objective: Nitric oxide stimulates the release of prostaglandins and cyclooxygenase, leading to cervical collagen rearrangement and cervical softening. Propranolol inhibits uterine beta-adrenergic receptors and induces uterine contractions. This study compared the efficacy and safety of oral and vaginal Isosorbide Mononitrate (IMN) and oral propranolol for cervical preparation. Materials & Methods: This randomized clinical trial was conducted on 120 pregnant women with an unfavorable cervix. They were assigned to four groups: vaginal IMN 40 mg, oral IMN 40 mg, oral propranolol 40 mg, and vaginal placebo tablets. In all groups, the specified agents were placed in the posterior fornix and administered every 4 hours up to a maximum of four doses. If labor did not start spontaneously, induction was performed with oxytocin. Results: The Bishop score in the vaginal IMN group increased significantly compared with the other groups (P<0.001). The interval from induction to the active phase and the mean duration of the active phase did not differ significantly among the four groups. Mild headache was significantly more frequent in the vaginal IMN group than in the other groups (P>0.001). The use of vaginal and oral isosorbide mononitrate tablets and oral propranolol had no adverse effects on the five-minute Apgar score or neonatal pH. Conclusion: Vaginal IMN is an effective, simple, and low-cost method for cervical preparation that can improve the Bishop score and shorten the induction period before the onset of the active phase. © 2026, Farname Inc. All rights reserved.