The pregnancy rate was found to be higher when GnRHa was used in a long protocol as compared to a short or ultrashort protocol. There was no evidence of a difference in live birth rate, but this outcome was only reported by three studies. There was no evidence of a difference in the outcomes amongst various long protocols; nor that stopping or reducing GnRHa at the start of stimulation was associated with a reduced pregnancy rate. For all comparison, except a long versus short protocol, there was a lack of power.
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.