Purpose: To determine if controlled ovarian hyperstimulation (COH) regimens using the gonadotropin releasing hormone (GnRH) agonist leuprolide acetate result in higher pregnancy and implantation rates than COH regimens using the GnRH antagonists cetrorelix or ganirelix following fresh and frozen embryo transfer. Methods: Retrospective analysis was performed evaluating the pregnancy rates with the first fresh and first frozen embryo transfer cycles according to which protocol was used. A haphazard decision was made on which protocol to use. Women were required to be < 40 years of age and have had ≥ 5 eggs retrieved. Results: Significantly lower implantation rates were seen with ganirelix compared to leuprolide acetate or cetrorelix. Conclusions: These data should hopefully encourage interest in a prospective study to determine if conclusions about the inferiority of ganirelix are not merely fortuitous.