Ovarian steroid hormones and endometrial response.

As a bioassay of the steroidogenic function of the corpus luteum, endometrial biopsy has been proposed as the most efficient way of diagnosing corpus luteum insufficiency. However, analysis of our data on luteal phase evaluation in infertility shows that most cases (86%) of endometrial luteal inadequacy are associated with normal hormone (progesterone, estradiol) stimulation. This apparent lack of endometrial progestational response may be explained by an end organ defect localized to the endometrial steroid receptors.