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.
Is long-protocol gonadotropin releasing hormone agonist administration superior to the short protocol in ovarian stimulation for in vitro fertilization?
To compare the long and short protocols of gonadotropin releasing hormone agonist (GnRH-a) administration for ovarian stimulation.
                University hospital.
                90 patients on their first attempt at in vitro fertilization and embryo transfer (IVF-ET).
                The results of two stimulation protocols were compared with respect to number of follicles greater than 17 mm, peak serum estradiol level, number of oocytes retrieved and fertilized, fertilization rate per oocyte, number of embryos transferred, and pregnancy rate per initiated cycle.
                The number of follicles greater than 17 mm and the peak estradiol level were significantly (P < .05) higher in the long protocol than those in the short protocol. The number of oocytes retrieved and fertilized, the number of embryos transferred, and the pregnancy rate per initiated cycle were also significantly (P < .001) higher in the long protocol than those in the short protocol. The fertilization rates per oocyte retrieved did not differ significantly between groups.
                The long protocol of gonadotropin releasing hormone agonist administration for ovarian stimulation in IVF-ET may be the preferred method when GnRH-a is used.