[Detection of corpus luteum insufficiency by histological study of the endometrium]

Characteristic morphologic alterations of endometrium following corpus luteum insufficiency are described. It is emphasized that in the majority of cases insufficiency of corpus luteum--which in 22 per cent of cases lies on the basis of functional sterility--brings about decreased output of progesterone in the luteal phase of the cycle and induces "disturbed secretion" i. e. hypoluteal transformation of endometrium. Another variant may also take place: normal function of the corpus luteum may last over a too short period inducing the shortening of the secretory phase and the early breakdown of the endometrium. Both, above mentioned mechanisms may inhibit the implantation of the fertilized ovum and lead to functional sterility.