Quantitative uterine histology during the menstrual cycle in relation to measured menstrual blood loss.

Endometrium and myometrium were collected at hysterectomy from 42 women with measured menstrual blood loss (range 4-840 ml). The specimens, obtained throughout the menstrual cycle, showed no evidence of organic disease on histological examination. The volume fraction occupied by arteries at the myometrial-endometrial junction, and by glandular tissue throughout the endometrium was estimated with a point counting technique. The index of volume-to-surface ratio of endometrial glandular tissue was examined by a combination of point counting and linear intercept methods. No correlation was found between menstrual blood loss and endometrial and myometrial arterial density, endometrial glandular density and volume-to-surface ratio. Consequently, menorrhagia, occurring in the absence of obvious pathology, does not appear to result from an excessive number of arteries of from abnormal glandular distribution.