Differences in gene expression provide evidence of progesterone resistance in midsecretory PCOS endometrium, independent of clomiphene citrate and corresponding to the observed phenotypes of hyperplasia, cancer, and poor reproductive outcomes in this group of women.

Histological endometrial dating does not reflect circulating P concentrations and cannot serve as a reliable bioassay of the quality of luteal function. Assessment of selected functional markers by either immunohistochemistry or qRT-PCR is similarly insensitive to decreased circulating P. Preliminary evidence suggests that abnormally low luteal phase serum P concentrations may have important functional consequences not otherwise detected.

No abstract

Eighteen normal women underwent pituitary down-regulation with leuprolide, followed by a 10-day treatment with 0.2 mg/d transdermal estradiol (E2) with subsequent allocation to one of two 10-day estradiol regimens plus 40 mg daily intramuscular P: supraphysiologic (0.2 mg/d transdermal E2 mg/d vaginal micronized E2) or subphysiologic (no exogenous E2 treatment). Average E2 and P in the supraphysiologic, physiologic, and subphysiologic groups were 1,175.9 pg/mL and 17.5 ng/mL, 136.9 pg/mL and 21.2 pg/mL, and 23.8 ng/mL and 22.0 ng/mL, respectively, and there were no differences between groups in endometrial histology or expression of biomarkers of receptivity.