A pilot study on the use of a 7-day course of letrozole followed by misoprostol for the termination of early pregnancy up to 63 days.

Background: Our previous randomized controlled study showed that the complete abortion rate in termination of pregnancy up to 63 days with the combined use of letrozole for 3 days followed by vaginal misoprostol was significantly higher than that of misoprostol alone. A positive correlation was observed between the basal estradiol level and the failure rate. We performed this pilot study to assess if a longer course of letrozole followed by misoprostol would improve the estradiol suppression and the complete abortion rate of pregnancy up to 63 days.

Study Design: Twenty subjects requesting legal termination of pregnancies up to 63 days were recruited. Medical abortion was offered with letrozole 10 mg daily for 7 days followed by vaginal misoprostol 800 mcg on the 7th day.

Results: Median induction-to-abortion interval was 7.5 h (range, 4.75-10.75 h). Overall complete abortion rate was 95%. All subjects with gestation ≤49 days (12/12) as well as 87.5% of subjects with gestation between 50 and 63 days (7/8) had complete abortion. No major adverse event were reported and over 88% of women would like to have medical termination as an option should it be required in the future.

Conclusion: This pilot study showed that a 7-day course of letrozole followed by vaginal misoprostol was associated with a very high complete abortion rate (95%) which is comparable to the standard regimen with sequential use of mifepristone and misoprostol in medical termination of early pregnancy up to 63 days.