بررسي نتايج حاصل از تجويز Letrozole( Aromatase Inhibitor )

Introduction: There is a problem with unsuccessful treatment cycles in women who suffer from PCOS or poorly respond to clomoiphene citrate (CC). Considering the results of Mitwally MF et al, 2001, we decided to evaluate the efficacy of aromatase inhibitors for induction of ovulation in such women. Material & Methods: According to the method, 20 women with PCOS who had not responded to CC participated in this study. A dose of 2.5 mg aromatase inhibitor letrozole was given orally on day 3-7 of cycles and sonography with estradiol level measurement were used to determine the ovulation status. Results: Only one of the twenty cases had one domain follicle (18 mm diameter) on day 12 of the cycle (Estradiol, 200 Pg/ml), IUI was then done without pregnancy outcome. In the remaining cases, repeated sonography was performed between day 9 & 15 of cycles and all cycles were cancelled due to absence of dominant follicle (> 14mm) E2 level in all cases were lower than 200 pg/ml and endometrial thickness was less than 8 mm. Conclusion: Our results did not confirm the favourable effects of letrozole used alone. In future, we are planning to use a combination regimen of letrozole plus CC or letrozole plus gonadotropin to evaluate the effect on similar patients.