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.
The routine use of gonadotropin-releasing hormone agonists for all patients undergoing in vitro fertilization. Is there any medical advantage? A prospective randomized study.
To determine if the routine use of gonadotropin-releasing hormone agonists (GnRH-a) for all patients undergoing in vitro fertilization (IVF) produces any significant medical advantage.
                Prospective randomized study.
                Three hundred eight patients having their first ever IVF attempt.
                Patients were randomly divided into four groups and received either human menopausal gonadotropin (hMG) alone for ovarian simulation (group A, n = 81); clomiphene citrate and hMG (group B, n = 77); a 3-day ultrashort course of GnRH-a and hMG (group C, n = 74); or pituitary desensitization with GnRH-a followed by hMG (group D, n = 76).
                The indications for IVF and mean age of all four groups of patients were comparable. There was a significant difference in the number of embryos cleaved and transferred among the groups, but there were no significant differences in the cancellation rate, mean number of oocytes collected or fertilized, and number of cases of failed fertilization. There were also no significant differences in the pregnancy and live birth rates per cycle commenced or per embryo transfer.
                The routine use of GnRH-a for all patients undergoing IVF has practical but no significant medical advantages.