Melatonin as a new drug for improving oocyte quality.

Although recent technical advances have benefited infertile couples, inadequate embryo development as a result of poor quality oocytes still contributes to infertility. The purpose of the present study was to evaluate melatonin as a drug for improving oocyte quality in such cases. Twenty-seven women from whom fewer than three fertilized embryos were grown and who failed to fall pregnant in previous treatment cycles were enrolled in the current prospective clinical study. Subjects took 1 mg or 3 mg tablets of melatonin orally at 22:00 h from the fifth day of the previous menstrual cycle to the day they were injected with human chorionic gonadotropin. The numbers of mature follicles, retrieved oocytes, degenerate oocytes, and fertilized embryos were compared to their previous data without melatonin (the control cycle). Intrafollicular melatonin concentrations were significantly increased, and intrafollicular lipid peroxide concentrations showed a tendency towards lower levels in the 3 mg melatonin treatment cycles compared with the control cycles. The number of degenerate oocytes was significantly reduced, and the number of fertilized embryos showed a tendency towards an increase in the 3 mg cycle compared to the control cycle. Three women succeeded in falling pregnant. Melatonin is likely to become the drug of choice for improving oocyte quality in women who cannot fall pregnant because of poor quality oocytes. (Reprod Med Biol 2003; : 139-144).