IRCT201103146063N1 IRCT 2011-06-02 Tehran University of Medical Science and Health Service The effect of metformin in different phenotypes of poly cystic ovary syndrome according to Rotterdam criteria criteria The effect of metformin in different phenotypes of poly cystic ovary syndrome according to Rotterdam criteria criteria 2010-07-07 anticipated 290 Complete https://irct.ir/trial/6517 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. 2 poly cystic ovary syndrome. Intervention 1: Intervention: metformin tablet 500 mg TDS from two months before starting ovulation induction, then ovulation induction started on day 2-6 of menstrual cycle with Letrozole 2.5 mg twice per day, when dominant follicle reached 18 mm , human chorionic gonadotropin 10000 IU was injected. Intervention 2: In control groups: no drug used before starting ovulation induction, then ovulation induction started on day 2-6 of menstrual cycle with Letrozole tablet 2.5 mg twice per day, when dominant follicle reached 18 mm, human chorionic gonadotropin 10000 IU was injected.