Progesterone resistance

Progesterone prepares the endometrium for blastocyst implantation and allows maintenance of pregnancy. The major sources of progesterone are the corpus luteum during the second half of the menstrual cycle and at the beginning of pregnancy, and the placenta. The main hormones responsible for stimulation of progesterone secretion are luteinizing hormone (LH) for the corpus luteum of the menstrual cycle and chorionic gonadotropin for the corpus luteum of pregnancy. Complete end-organ resistance to progesterone would be incompatible with reproductive competence in females. Males would not be expected to be affected since progesterone has no known function in men. Failure of the uterus to respond to progesterone would lead to the development of a 'constantly proliferative' endometrium incompatible with blastocyst implantation. Partial resistance to progesterone, on the other hand, would be expected to be associated with various degrees of incomplete maturation of the endometrium, perhaps expressed clinically as infertility or early abortions. The syndrome would present with the clinical and histologic picture of a luteal phase defect in which the life span of the corpus luteum and the plasma progesterone concentrations would be normal or elevated. [from OMIM]