Letrozole Plus Misoprostol versus Misoprostol Alone in Induction of Anembryonic Missed Abortion: A Randomized Controlled Trial

Abstract

Abstract Background: letrozole is a third-generation aromatase inhibitor approved for breast cancer therapy. According to many recent studies, letrozole given for three days before the administration of misoprostol was more effective than misoprostol alone at inducing abortion. Our study compared the efficacy of various letrozole regimens (10 mg/d for three days and a single dose of 20 mg) combined with misoprostol vs. misoprostol alone in inducing abortion. Methodology: Using a computer-generated randomization list and sequentially numbered sealed envelopes, we randomly divided 96 patients with anembryonic missed abortions into three equal groups (a single-dose letrozole group, a multiple-dose letrozole group, and a misoprostol-only group). Age, BMI, gestational age according to LMP, complete abortion rate, incomplete abortion rate, missed abortion rate, and induction-to-abortion interval were all collected. Results: The complete abortion rate was significantly higher in the single-dose letrozole and the multiple-dose letrozole groups than in the misoprostol group (p-values = 0.0455 and 0.001, respectively). On the other hand, there was no significant difference in the complete abortion rate between the single-dose group and the multiple-dose letrozole group (p-value = 0.1713). The time to complete abortion was significantly shorter in the single-dose and multiple-dose letrozole groups than in the misoprostol group (p-values = 0.0036 and 0.0049, respectively). On the other hand, there was no significant difference in the time to complete abortion between the single-dose letrozole group and the multiple-dose letrozole group (P = 0.532). Conclusion: Single- and multiple-dose letrozole regimens followed by misoprostol had a higher rate and a shorter time to complete abortion than misoprostol alone. Administering a single-dose regimen of letrozole has the benefit of being more convenient and may improve patient compliance, but for its universal use, there is a need for more randomized controlled trials. Trial registration: The trial is registered at gov with the name " Letrozole and abortion" and the identifier " NCT05198050." The date of registration was April 1, 2022, registered prospectively. URL: https://register.clinicaltrials.gov/prs/app/action/ViewOrUnrelease?uid=U0004GED&ts=25&sid=S000BPDQ&cx=43mobl