The value of the progesterone-to-estradiol ratio on the day of hCG administration in predicting ongoing pregnancy and live birth rates in normoresponders undergoing GnRH antagonist cycles.

Objective: To investigate the relationship of the progesterone-to-estradiol (P/E2) ratio on the day of hCG administration with ongoing pregnancy rates in patients with normal ovarian reserve undergoing GnRH antagonist cycles.

Study Design: Observational cohort study including 129 women with normal ovarian reserve undergoing the GnRH antagonist protocol at the IVF unit of Ankara University School of Medicine. Receiver operating characteristics (ROC) analysis was performed to determine cut-off values for the P/E2 ratio detrimental to IVF/ICSI-ET outcomes.