Infertile PCOS patients who had three previous ovulatory cycles under CC will be enrolled and randomized in three groups (groups A, B, and C). In group A, patients will receive cyclic progestogens for nine months; in group B, patients will continue CC treatment for further three cycles at the same ovulating doses followed by six months of cyclic progestogens; and in group C, patients will continue CC administration at the same ovulating doses for nine cycles. In each case, CC will be administered using a traditional incremental-doses protocol up to 150 mg daily.