Ovulation and pregnancy rates with tomoxifen in clomiphene resistant polycystic ovarian syndrome patients

Background and Çhronic annovulation is a common cause of infertility in women and polycystic ovarian syndrome (PÇÔS) is the most common cause of anovulation. Ôvulation induction with clomiphene is the first line of therapy in pcos. 20-22% of the patients may be resistant to clomiphene. The objective of this study was to assess the ovulation and pregnancy rates with tamoxifen in clomiphene resistant PÇÔS patients. This is a descriptive study on 100 patients with PÇÔS and resistance to clomiphene reffered to infertility clinic of Ïmam Hospital in Sari, Ïran. patients were given tamoxifen 40 mg/d from the third to seventh day of the cycle. Treatment was monitored by serial vaginal sonography. hÇG was administered 10/000 unit ÏM when 1-3 follicles were >18mm. Ôvulation rate based on (midluteal progesteron level>3ng/ml) and clinical pregnancy rate were assessd. The ovulation rate was 27%. gestational sac was seen in 18 patients (18%). The study showed that endometrial thickness was 10.72 mm in pregnant versus 8/16 mm in nonpregnant subjeots with significant differences (p<0/05). The number of dominant follicles >16mm were 3/4 in pregnant versus 2.7 in nonpregnant (p<0/05) with significant differences. Çonclusion: This study showed that tamoxifen is usefull in inducting ovulation and pregnancy in clomiphene-resistant PÇÔS patients by increasing the endometrial thickness and dominant follicle due to estrogen agonist effect.