Pseudocorpus luteum insufficiency: a study of cytosol progesterone receptors in human endometrium.

This prospective, controlled study of 38 women was designed to compare the number of endometrial cytosol progesterone receptor (PRc) binding sites in infertile women with documented luteal phase defect with those of similar women without luteal phase defect. A 25% reduction in PRc binding sites was observed in women with luteal phase defect (P less than .05). Considerable overlap was noted between luteal phase defect and control groups; thus, no definite range of binding site numbers was predictive of luteal phase defect. The results of this study, therefore, suggest that an end-organ receptor defect may exist in some women with luteal phase abnormalities.