IRCT2013072814189N1 IRCT 2014-06-14 Vice chancellor for research affairs, Shiraz University of Medical Sciences The effects of letrozole in treatment of infertility The comparison between infertile women with clomiphene citrate resistant polycystic ovary syndrome (PCOS) undergoing intrauterine insemination (IUI) who receive letrozole and those who did not in prevention of premature luteinizing hormone (LH) surge 2011-07-23 anticipated 140 Complete https://irct.ir/trial/13832 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Not used, Assignment: Parallel, Purpose: Prevention, Other design features: One hundred fourty patients with infertility due to polycystic ovary syndrome are randomly divided into 2 groups of 70. Both groups are equal regarding their age averages. The intervention group (group 2) is given letrozole and control one is received placebo. Since the study was a single blind one, patients do not know which one is medication and which one is placebo. N/A polycystic ovarian syndrome. Intervention 1: Intervention1: Letrozole( Letrozole Soha, Soha Pharmaceutical Company, Karaj, Iran), 2 tab 2.5 mg orally, since the 8th day up to human chorionic gonadotropin injections. Intervention 2: Intervention 2: Placebo, 2 tab 2.5 mg orally, since the 8th day up to human chorionic gonadotropin injections.