The range of subtle rise in serum progesterone levels following controlled ovarian hyperstimulation associated with lower in vitro fertilization pregnancy rates is determined by the source of manufacturer.

Two previous studies found a correlation of higher pregnancy rates (PRs) with lower serum progesterone (P) levels at the time of human chorionic gonadotropin (hCG) injection in in vitro fertilization (IVF) cycles when luteal phase leuprolide acetate (LA)-human menopausal gonadotropin (hMG) was used for the controlled ovarian hyperstimulation (COH) regimen. In these two studies the radioimmunoassay (RIA) by Diagnostic Products Corporation (DPC) was used to measure P levels. This study attempted to corroborate these findings using a different RIA for P (Amersham) when the same COH regime was administered. The PR was significantly higher in the group where P was < or = 1 ng/ml at the time of hCG (43.2%) versus the groups where the P level ranged from 1.1 to 2 ng/ml (15.8%). Viable PRs were also significantly higher in the lower P group. In contrast to the previous data with the DPC assay, no differences were seen with P < 0.5 ng/ml (36.4%) versus 0.5-1 ng/ml (44.6%). Nevertheless, using the Amersham RIA, the data does suggest decreasing PRs with higher serum P levels at time of hCG when using luteal phase LA-hMG COH regimen.