ABSTRACT
To compare the clinical outcomes between letrozole and clomiphene citrate [cc] combined with gonadotropins in Clomiphene - resistant polycystic ovary syndrome [PCOS] patients. One hundred and twenty PCOS women after clomiphene response failure were randomly divided into two equal groups to receive clomiphene [100 mg/day] or letrozole [5mg/ day] on days 3-7 of menstrual cycle, combined with human menopausal gonadotropin at a dose 150 IU on days 5-8. The number of dominant follicles, consumed gonadotropin ampoules, endometrial thickness, and clinical pregnancy rates were compared. No significant difference was found regarding the number of dominant follicles, endometrial thickness and consumed gonadotropin ampoules between letrozole and CC groups. Although, the pregnancy rate in letrozole group was higher than that of the CC, the difference was not significant [36.7% vs. 33.3%, p=0.702]. In clomiphene - resistant PCOS patients, similar to Clomiphene, letrozole in combined regimens with gonadotropin can be effective for the induction of ovulation