Influence of Progesterone/Estradiol Ratio on Luteal Function for Achieving Pregnancy in Gonadotropin Therapy

Abstract

The purpose of this study was to evaluate the influence of the relationship between plasma progesterone (P₄) and estradiol (E₂) levels in the luteal phase for achieving pregnancy in human menopausal gonadotropin (hMG)-human chorionic gonadotropin (hCG)-treated cycles. Plasma P₄ and E₂ levels were determined in 93 hMG-hCG-treated cycles (23 pregnant and 70 nonpregnant) of 46 patients during 3 periods of the luteal phase, using radioimmunoassay. In addition, 88 spontaneous ovulatory cycles and 100 clomiphene-treated cycles were also studied in the same manner. In hMG-hCG-treated cycles in the early luteal phase, the P₄/E₂ ratio in pregnant cycles was significantly higher than that in nonpregnant cycles. There was no significant difference between the P₄/E₂ratios of the luteal phase of hMG-hCG-treated pregnant-group, clomiphene-treated and spontaneous ovulatory cycles. In nonpregnant cycles, however, the P₄/E₂ ratio in hMG-hCG-treated cycles was significantly lower than that in clomiphene-treated or spontaneous ovulatory cycles. These results suggest that in hMG-hCG-treated cycles, the P₄/E₂ ratio may be a more reliable index of luteal function for achieving pregnancy than P₄ levels alone.