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

Objective: 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. Design: Randomized, prospective, single, first cycle study. Setting: University teaching hospital. Patients: Eight-six infertile couples undergoing IVF-ET attempt under rules for Ireland. Intervention: Gonadotropin-releasing hormone agonist administered intranasally from day 1 or 21 of menstrual cycle. Human menopausal gonadotropin commenced when pituitary downregulation was confirmed. Main Outcome Measures: Ovarian response, cancellation, fertilization, and pregnancy rates. Results: 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. Conclusions: 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.