Investigating the comparative effect of combined regimens of letrozole with misoprostol alone for first trimester medical abortion

Medical management of miscarriage in the first trimester is performed with multiple-medication regimens. We aimed to compare the efficacy and complications of combined regimen of letrozole and misoprostol with misoprostol alone for first trimester medical abortion.

A retrospective cohort study was conducted at Babol University of Medical Sciences for medical abortion at gestational age less than 12 weeks. All pregnant women in the first trimester with indications for abortion between 2014 and 2015 and treated by the combined regimen of letrozole and misoprostol or misoprostol alone were included in this study. The successful complete abortion, the frequency need for curettage, the induction-abortion interval, drug complications, hemoglobin, and hematocrit ratio were all retrieved from the patients’ documents.

During the study period, 110 pregnant women were admitted to our hospital for medical abortion at the first trimester and were considered for medical management. Of these, 40 women received letrozole 7.5 mg for two days, followed by misoprostol 800 mcg vaginally. Seventy women received only misoprostol 800 mcg vaginally. Follow-up for abortion was usually done 24 hours after the medical management. The successful complete abortion rate in the combined regimen of letrozole and misoprostol was more than that of the misoprostol alone group (75.0% vs. 31.4%; P= 0.001). The frequency need for curettage (P=0.001) and the mean induction-abortion interval (P= 0.021) were lower in combined regimen of letrozole than misoprostol alone group. The drug complications, hemoglobin ratio and hematocrit ratio were similar between the groups.

Our study suggested that letrozole enhances the misoprostol effect in the first trimester of pregnancy termination and decreases some of its complications.