A randomized prospective study of early follicular or midluteal initiation of long protocol gonadotropin-releasing hormone in an in vitro fertilization program

To determine the optimum menstrual cycle time to initiate a long-protocol gonadotropin-releasing hormone agonist (GnRH-a) down-regulation regimen before hMG stimulation before IVF. Randomized, prospective, single, first cycle study. University teaching hospital. Eighty-six infertile couples undergoing IVF-ET attempt under rules for Ireland. Gonadotropin-releasing hormone agonist administered intranasally from day 1 or 21 of menstrual cycle. Human menopausal gonadotropin commenced when pituitary down-regulation was confirmed. Ovarian response, cancellation, fertilization, and pregnancy rates. No significant differences found between day 1 and day 21 initiation. But starting on day 1 is more easily recognizable by patients and avoids the possibility of administering GnRH-a in the presence of an unsuspected pregnancy. Both follicular and luteal phase initiation of GnRH-a long-protocol down-regulation are equally efficacious. In our clinical context, patients and management favor commencing on day 1.