After two months of DHEA/placebo treatment, the subjects will then be given a standard low dose ovarian stimulation with 75 IU intramuscular human menopausal gonadotrophin (HMG, Menogon®, Ferring Pharmaceuticals) daily for 7 days. Blood tests and pelvic ultrasound scan will be repeated after 7 days of stimulation (ie. on day 10 or 11).