Dating of the endometrium by microhysteroscopy.

In 173 consecutive cases of hysteroscopy, the microhysteroscope was brought into contact with the anterior part of the fundus uteri. The vascular pattern of the endometrium was then visualized and photographed. As the vascularization of the endometrium changes during the menstrual cycle, a dating of the endometrium was made based on the blood vessel pattern. An endometrial biopsy was taken in each case. Hysteroscopically we were able to define five different phases in the menstrual cycle: early proliferative, late proliferative, early secretory, late secretory, and premenstrual-menstrual phase. Histopathological examination confirmed the hysteroscopical diagnosis of the phases in 72, 69.7, 81.3, 53.8 and 70%, respectively.