Sublingual or oral versus vaginal misoprostol for cervical priming prior to first-trimester surgical abortion: a systematic review and meta-analysis.

Abstract

To compare the efficacy of oral or sublingual misoprostol vs the vaginal route for cervical preparation prior to first-trimester surgical abortion. This systematic review and meta-analysis assessed baseline cervical dilation, intraoperative blood loss, and operating time to guide clinical decision-making. Web-based databases were systematically searched using relevant keywords to identify all published studies on misoprostol for cervical preparation prior to first-trimester surgical abortion. Randomized controlled trials including women undergoing first-trimester surgical abortion were eligible. Studies compared oral or sublingual misoprostol with vaginal misoprostol and reported at least one of the following outcomes: cervical dilatation, blood loss, or operating time. Two authors independently screened studies, extracted data, and assessed risk of bias using the Cochrane Risk of Bias tool. Continuous outcomes were analyzed using random-effects meta-analysis, with weighted mean differences and 95% confidence intervals. Heterogeneity was assessed using the I² statistic. Twenty-one trials comprising 4380 patients were included: 1246 (28.4%) received sublingual, 1038 (23.8%) oral, and 2096 (47.8%) vaginal misoprostol. Comparisons were performed separately for oral vs vaginal and sublingual vs vaginal administration. Both sublingual and oral misoprostol showed comparable efficacy to the vaginal route, with no considerable differences in baseline cervical dilation, intraoperative blood loss, or procedure duration. Although the sublingual route showed a statistically shorter procedure duration compared to the vaginal route (Weighted Mean Difference=-0.89 minutes; 95% confidence interval, -1.55 to 0.23; P=.008; I²=86%), this difference is not clinically meaningful. Given the similar efficacy across routes, the sublingual and oral routes may be preferred in clinical practice due to their practical advantages, including easier administration and the avoidance of invasive manipulation or vaginal examination, while final decisions should consider patient preference, resource availability, and institutional protocols.