In this prospective interventional study, the patients of both groups will receive the same induction protocol for controlled ovarian hyperstimulation which is the long protocol, our standard protocol in the center. Initial suppression of ovarian function with gonadotrophin releasing hormone agonist will start on day 21 of the preceeding cycle. Human menopausal gonadotrophin induction will start after confirmed ovarian down regulation by both laboratory investigations and ultrasound by daily intramuscular injection of 150-300 IU (Merional, IBSA) until at least 3 follicles reach 18 mm and serum estradiol level lies between 1000-4000 then 10000 IU, HCG is given.