Single dose letrozole and misoprostol for termination of pregnancy through 63 days' gestation: A pilot study

Objectives: We conducted a pilot study to evaluate a single dose of letrozole 30 mg prior to misoprostol 800 mcg buccally for medication abortion STUDY DESIGN: We enrolled 40 participants seeking medication abortion up to 63 days' gestation at a site in Salt Lake City, UT. Participants received a single dose of letrozole 30 mg in-clinic followed 2 days later by misoprostol 800 mcg buccally at home. They took a second dose of misoprostol if they had no bleeding within 24 hours of the first. Participants returned 7 to 10 days later for assessment of abortion outcome and side effects RESULTS: Thirty-seven participants (93%) returned for follow-up and 2 (5%) went to another facility from which research staff obtained outcome data. Three-fourths (29/39, 74%, 95% CI: 60%-89%) had a complete abortion; 4 (10%, 95% CI: 0.3%-20%) had an incomplete abortion and opted for aspiration, and 6 (15%, 95% CI: 4%-27%) had an ongoing pregnancy. All subjects with follow-up reported taking the first dose of misoprostol. Ten (27%) took the second dose as well; only three did so due to no bleeding. Nineteen participants (51%) reported side effects after letrozole prior to misoprostol and two people (5%) rated these effects as severe. Side effects following misoprostol occurred in 33 participants (89%) and were as expected based on previous literature. No serious adverse events were reported CONCLUSION: A single dose of letrozole 30 mg followed by misoprostol had lower than desirable efficacy and does not warrant further study.

Implications: A single dose of letrozole does not appear to be an effective adjunct to misoprostol for medication abortion.