In group 3, injection of GnRH agonist (Superfact) at a subcutaneous daily dose of 0.5 mg is started on the day 17-19 of the natural menstrual cycle. Once pituitary desensitization is confirmed, hormonal treatment is commenced with 4mg/day oral Estradiol valerate and after 7 days if endometrial thickness is adequate, Estradiol administration will be continued with the same dose and 100mg Progesterone is administered before embryo transfer, otherwise patients are candidates for higher dosage of Estradiol till favourable endometrial thickness is achieved.