The efficiency of progesterone/estradiol and progesterone/follicle ratio without elevated trigger-day progesterone levels on the reproductive outcomes of GnRH antagonist IVF/ICSI cycles.

The P/E2 and P/F ratios were found to be more efficient and reliable markers than serum progesterone level alone in predicting the reproductive outcomes of assisted reproduction cycles without a premature rise in serum progesterone levels. A P/E2 ratio ≤0.36 and a P/F ratio ≤0.17 significantly improved the cycle outcomes.