Changes in endometrial wave-like movements in accordance with the phases of menstrual cycle.

Objective: To investigate whether endometrial wave-like movements change with phases of the menstrual cycle. Methods: Endometrial wave-like movements were observed by transvaginal sonographic tomography during 50 menstrual cycles of 20 regularly menstruating women. Results: Endometrial wave-like movements were not observed during the early follicular phase. These movements proceeded perpendicularly to the longitudinal uterine axis and appeared at the midfollicular phase. In the periovulatory phase, waves reached a peak and moved from cervix to fundus. In the postovulatory phase, endometrial wave-like movements became parallel to the longitudinal uterine axis. In the midluteal phase, most of these waves disappeared. Immediately before menstruation, the waves reappeared moving from fundus to cervix. These movements continued until day 1 of the subsequent menstrual phase. Conclusion: Endometrial wave-like movements change with the passage of menstrual cycle. They appear to play an important role in the transport of sperm and cervical mucus and the excretion of menstrual flow.