Methods a prospective observational study conducted on 196 women with Polycystic ovary syndrome divided into two groups Group 1 98 patients received 100mg of clomiphene citrate daily for 5 days starting on second cycle day and Group 2 98 patients received 100mg of clomiphene citrate daily starting in the luteal phase before onset of withdrawal bleeding for 5 days. aromatase inhibitors vs tamoxifen