In the letrozole group, withdrawal bleeding was achieved using 10 mg of dydrogesterone tablets for 10 days before stimulation, then 2.5 mg of letrozole oral tablets (Femara; Novartis Pharma Services, Switzerland) daily from day 3 of the menses for 5 days up to six cycles. All patients in the control group underwent laparoscopic ovarian diathermy, then followed up for 6 months.