Efficacy of Oral and Vaginal Misoprostol in Medical Termination of Second-Trimester Pregnancy: A Randomized Controlled Trial

Abstract

Background: Second-trimester medical termination of pregnancy is an important component of obstetric care, particularly in cases of fetal demise, congenital anomalies, and other medically indicated conditions. Compared with first-trimester termination, second-trimester abortion is associated with longer induction time, greater procedural complexity, and a higher risk of complications. Misoprostol, a synthetic prostaglandin E1 analogue, is widely used for this purpose because it is inexpensive, stable at room temperature, and effective through different routes of administration. However, the most effective route for second-trimester pregnancy termination remains a subject of clinical interest.

Objective: To compare the efficacy of oral and vaginal misoprostol in the medical termination of second-trimester pregnancy.

Methods: This randomized controlled trial was conducted in the Department of Obstetrics and Gynecology, Recep Tayyip Erdogan Hospital, Muzaffargarh, over a period of six months after approval of the synopsis. A total of 200 women with pregnancies between 12 and 20 weeks of gestation were enrolled and randomly allocated into two equal groups. Group A received vaginal misoprostol, and Group B received oral misoprostol. In both groups, misoprostol was administered in a dose of 400 µg every 4 hours, up to a maximum of four doses. The primary outcome was efficacy, defined as complete abortion without operative intervention. Secondary outcomes included abortion within 24 hours, induction-abortion interval, dose requirement, and need for operative evacuation.

Results: Complete abortion occurred in 75.0% of women in the vaginal misoprostol group compared with 55.0% in the oral misoprostol group. Abortion within 24 hours was achieved in 82.0% of the vaginal group and 65.0% of the oral group. The mean induction-abortion interval was shorter in the vaginal group (15.60 hours) than in the oral group (20.31 hours). The vaginal group also required fewer doses and a lower total dose of misoprostol, and fewer women required operative evacuation compared with the oral group.

Conclusion: Vaginal misoprostol was more effective than oral misoprostol in second-trimester medical termination of pregnancy. It was associated with a higher complete abortion rate, shorter induction-abortion interval, lower dose requirement, and reduced need for operative evacuation. Vaginal misoprostol may therefore be considered the preferable route in similar clinical settings.