Sublingual vs vaginal misoprostol for completion of first trimester missed abortion: a randomised controlled trial

Abstract

Objective: The study aimed to compare the efficacy and safety of sublingual and vaginal misoprostol for termination of pregnancy in women with first trimester missed abortion.

Methods: A single-blind, parallel group, randomised clinical trial (ClinicalTrials.gov NCT02686840) was conducted in a university hospital between 1 February 2016 and 31 January 2017. All women who presented with first trimester missed abortion were invited to participate in the study and were randomised to one of two groups: one group received sublingual misoprostol in three doses of 800 μg every 4 h, while a second group received vaginal misoprostol in the same dosage regimen. The primary outcome of the study was the rate of complete abortion within 7 days after initiation of treatment.

Results: The study included 200 women (100 in each arm). By day 7, successful complete abortion was significantly more frequent in the sublingual misoprostol group (71.4%) than in the vaginal misoprostol group (51.5%) (p = .006). By day 30, the rate of complete abortion was higher in the sublingual misoprostol group (90.6%) than in the vaginal misoprostol group (83.9%), but with no statistically significant difference (p = .164). The mean length of the induction-expulsion interval in the sublingual misoprostol group was significantly shorter compared with the vaginal misoprostol group (12.3 ± 3.1 h vs 16.4 ± 4.2 h, respectively; p = .001) and the sublingual misoprostol group had a smaller drop in haemoglobin level (p = .001). The side effects of misoprostol were significantly more frequent in the sublingual group compared with the vaginal group.

Conclusion: Sublingual misoprostol is more effective than vaginal misoprostol in completing first trimester missed abortion, with a shorter induction-expulsion time. Sublingual misoprostol is, however, associated with more side effects, such as unpleasant taste, gastrointestinal symptoms and fever, compared with vaginal misoprostol.

Keywords: Misoprostol; missed abortion; prostaglandins; sublingual; vaginal.