Higher pregnancy rates (PRs) following in vitro fertilization-embryo transfer (IVF-ET) with luteal phase leuprolide acetate (LA)/gonadotropin hyperstimulation regimen if serum estradiol (E-2) increases by at least 10% the day after human chorionic gonadotropin (hCG)

The objective of this study was to determine if the change in serum estradiol (E-2) the day following human chorionic gonadotropin (hCG) in in vitro fertilization (IVF) cycles using the luteal phase leuprolide acetate (LA)/human menopausal gonadotropin (hMG) ovarian hyperstimulation protocol was associated with pregnancy rates (PRs). The clinical PR increased as the change in E-2 increased: 0% PR if E-2 decreased by more than 10%; 12.2% PR if E-2 remained within 10% of the level on day of hCG; and 23.8% PR if E-2 increased by more than 10%. Based on these results, the clinician should consider deferring embryo transfer if the E-2 levels decreased.