1. In most of the cases with secretory hypoplasia of endometrium detected by the dating diagnosis method (Noyes and Hertig, 1950), atypical diphasic variation is observed on the curve of body temperature (B. B. T.) of patient.
2. Total and daily urinary excretion of pregnanediol are decreased in patients with the secretory hypoplasia, and no peak is seen corresponding to the bloom stage (the stage of maturlty) of corpus luteum.
3. Urinary excretion of pregnanediol is, however, not recovered to normal following administration of human chorionic gonadotrophin. The fact may indicate that some of the secretory hypoplasia is not merely ascribable to corpus luteum insufficiency, but includes a certain abnormality in morphological and physiological responsiveness of the endometrium itself.
4. Accordingly, to make a diagnosis as corpus luteum insufficiency, various clinical investigations to deduce function of ovary itself should be made in addition to ordinary histological observations on the endometrium. The pathological state described as the corpus luteum insufficiency is not a simle disease but symptom-complex in which some pathological states may possibly be distinguished.
5. A Corpus luteum insufficiency deducod by findings in B. B. T. is frequent in case of polymenorrhea with 15 to 24 days cycle, but rather few in number in case of normal menstrual cycle.
6. Daily administration of human chorionic gonadotrophin can improve corpus luteum insufficiency at a dose of 1, 000/I. U. Further, the treatment is effective on improvement of corpus luteum function in next menstrual cycle.
