Relationship of progesterone/estradiol ratio on day of hCG administration and pregnancy outcomes in high responders undergoing in vitro fertilization

Objective: To evaluate the predictive value of a serum P/E-2 ratio measured on the day of hCG administration regarding pregnancy outcomes in high responders undergoing IVF. Design: Retrospective study. Setting: Teaching hospital. Patient(s): Two hundred twenty-three infertile women classified as high responders in IVF-ET cycles. Intervention(s): Eligible infertile women undergoing IVF were assigned to four groups according to serum P levels on the day of hCG administration: group 1, P <= 0.9 ng/mL; group 2, 0.9 < P <= 1.4 ng/mL; group 3, 1.4 < P <= 2.0 ng/mL; group 4, P > 2.0 ng/mL. The relationship of E-2 level and P/E-2 ratio on the day of hCG administration and pregnancy outcomes was analyzed. Main Outcome Measure(s): Implantation and pregnancy rate. Result(s): Patients in group 4 had highest E-2 level and P/E-2 ratio, as well as lowest implantation and pregnancy rates. Using P for grouping, the sensitivity/positive predictive values (%/%) of P/E-2 ratio in the four groups were 15/66, 30/65, 30/60, and 25/41, respectively. Conclusion(s): Using the level of a single sex hormone on hCG day to predict pregnancy outcome in high responders undergoing IVF is confounding, whereas using a P/E-2 ratio on hCG day is theoretically reasonable. However, the low sensitivity and positive predictive value make the use of P/E-2 clinically unfeasible. (Fertil Steril (R) 2009;92:1284-9. (C) 2009 by American Society for Reproductive Medicine.)