The relationship of the corpus luteum and the endometrium in infertile patients.

A group of 50 females undergoing an infertility work-up had measurements of serum progesterone levels in all cases, endometrial sampling in 49, and biopsy of a grossly identifiable corpus luteum in 42 cases. Of the 41 cases with three parameters available for study, 39 had correlations of all three parameters. The remaining nine cases had two of three parameters available for study. Of these, three showed a secretory endometrium but absent corpus luteum and an anovulatory progesterone level, and a patient showing a proliferative-phase endometrium at the same time had an ovulatory progesterone level and a postovulatory corpus luteum. The evidence presented suggests that, among the three parameters tested, the progesterone level as a noninvasive procedure serves as a good index of ovulation 92% of the time, and occasionally endometrial histologic sampling does not necessarily reflect ovarian function.