Body mass index–associated differences in response to ovulation induction with letrozole

Objective To compare occurrence of pregnancy among obese (body mass index [BMI] ≥30) and nonobese (BMI Design Retrospective cohort study. Setting Academic reproductive endocrinology and infertility clinic. Patient(s) Ninety women with a variety of infertility diagnoses. Intervention(s) Letrozole (5 mg) on menstrual cycle days 3–7, followed by intrauterine insemination (IUI). Main Outcome Measure(s) Occurrence of pregnancy and pregnancy outcomes. Result(s) Ninety women underwent 180 letrozole-IUI cycles. Conception of pregnancy occurred in 10.4% and 18.2% of the BMI Conclusion(s) Our study of 90 women undergoing letrozole-IUI treatment showed greater likelihood of pregnancy in higher-BMI women, although the difference was not significant. Letrozole is an effective ovulation induction agent in higher-BMI women.