This work discusses the latest medical research aimed at helping women who have difficulties in their menstrual cycle which result in infertility. The area of particular interest is the use of hormones, especially human chorlonic gonadotropin (hCG) and luteinizing hormone (LH), to artificially mimic the natural menstrual cycle and enhance fertility. The chapters explain the current knowledge on how the female reproductive system works, the problems that occur, and presents some of the latest research on how various international groups are trying to overcome the difficulties. The book is the proceedings of an international symposium held under the auspices of the French Endocrinology Society, 19-20 June, 1993.