Effect of misoprostol with and without letrozole on the induction of abortion for women with first-trimester missed abortion

Objective To determine whether addition of letrozole to a misoprostol-based abortion regimen can increase the rate of complete abortion. Methods The randomized, placebo-controlled, double-blind trial enrolled women with missed abortion in the first trimester of pregnancy attending Sadooghi Hospital, Isfahan, Iran, from 2016 to 2018. The women were randomly assigned to the study group, which received 10 mg of letrozole daily for 3 days, followed by two doses of 800 mu g of vaginal misoprostol at a 4-hour interval, or the control group, which received a placebo, followed by the same dose of misoprostol. Sonography was performed to check the abortion status. Results In total, 120 women completed the study: 60 in the misoprostol plus letrozole group, and 60 in the misoprostol only group. Complete abortion was documented for 93 (77.5%) women: 48 (80.0%) in the misoprostol plus letrozole group and 45 (75.0%) in the misoprostol only group (P=0.80). The mean duration of induction in the misoprostol plus letrozole and misoprostol only groups was 7.35 +/- 3.54 hours and 8.2 +/- 3.8 4hours, respectively (P=0.21). Conclusion Administration of misoprostol alone was found to be as effective as the administration of misoprostol plus letrozole for first-trimester missed abortion.