Comparison of Using Misoprostol with or without Letrozole in Abortion Induction: A Placebo-Controlled Clinical Trial

Aims The rate of induced abortion is growing worldwide. In this study, we aimed at comparing using misoprostol with or without Letrozole in abortion. Materials and Methods In this placebo-controlled trial, 46 women with a gestational age of fewer than 20 weeks, who were candidates of legal abortion, were selected by simple randomization sampling method and randomly assigned into two groups. Drug group received 10mg daily Letrozole (4 tablets of 2.5mg) for 3 days prior to taking Misoprostol and the placebo group received daily placebo (4 tablets with the exact appearance of Letrozole) with the same instructions. After 3 days, Misoprostol was given to all the participants based on their gestational ages. The data were analyzed by SPSS 16 software, using independent sample t-test and Chi-square test. Findings 21 women (45.7%) had a successful complete abortion, and curettage was needed for 25 women (54.3%). Successful abortion rate was significantly higher in the group receiving Letrozole (78.3%) than the group receiving placebo (13.0%; p=0.0001). Mean induction-abortion interval was 22.61±7.721 hours in the drug group and 24.09±8.251 hours in the placebo group, which was not significantly different (p>0.05). There was no significant difference between the two groups in terms of vaginal bleeding and adverse effects. Conclusion Using 10mg daily Letrozole for 3 days followed by oral Misoprostol results in a significantly higher rate of complete abortion compared with placebo in women with a gestational age of less than 20 weeks.