An increased serum progesterone-to-estradiol ratio on the day of human chorionic gonadotropin administration does not have a negative impact on clinical pregnancy rate in women with normal ovarian reserve treated with a long gonadotropin releasing hormone agonist protocol.

Objective: To evaluate the relationship between serum P:E(2) ratio on the day of hCG administration and the clinical outcomes in infertile women with normal ovarian reserve treated with a long GnRH agonist (GnRH-a) protocol.

Design: Retrospective analysis of IVF-embryo transfer data.

Setting: University teaching hospital.

Patient(s): One hundred thirty-nine infertile women with normal ovarian reserve, who received IVF-embryo transfer with a long GnRH-a protocol.

Intervention(s): Cycles were grouped according to whether premature luteinization (PL) appeared on the day of hCG administration. Premature luteinization was defined as a P:E(2) ratio >or=1.2 by using receiver operator characteristic analysis.

Main Outcome Measure(s): Treatment cycle hormonal characteristics and clinical outcomes.

Result(s): The P:E(2) ratio on the day of hCG administration was significantly higher in the PL (n = 41) compared with the non-PL (n = 98) group (2.4 +/- 1.5 and 0.6 +/- 0.3, respectively). The mean number of oocytes retrieved in the PL and non-PL groups were 4.2 +/- 2.8 and 12.7 +/- 6.6, respectively. However, the difference between the clinical pregnancy rates (PR) in the PL and non-PL groups was not statistically significant (29.3% vs. 34.5%). In a logistic regression analysis, the P:E(2) ratio showed no statistically significant correlation with pregnancy outcome.

Conclusion(s): The increased serum P:E(2) ratio on the day of hCG administration, as an indicator of PL, has a poor predictive value on IVF outcomes in infertile women with normal ovarian reserve treated with a long GnRH-a protocol.