Subendometrial contractility in menstrual phase visualized by transvaginal sonography in patients with endometriosis

OBJECTIVE: To describe the propagation direction of the subendometrial myometrial contractile wave in menstrual phase sonographically assessed in patients with and without endometriosis. DESIGN: Prospective study. SETTING: Patients and normal volunteers in a university hospital. PATIENTS: Sixteen women with (study group) and 21 without (control group) endometriosis. INTERVENTIONS: Patients were examined by transvaginal sonography (midsaggital plane of the uterus) and recorded on videotape for a 5-minute period. MAIN OUTCOME MEASURE: Direction of propagation of contraction waves. RESULTS: The endometriosis group showed a predominant retrograde pattern whereas the control group showed a normal antegrade. CONCLUSION: This abnormal cervix-to-fundus myometrial activity could well increase the amount of peritoneal shedding of endometrial menstrual debris, increasing the probabilities of its heterotopic implantation.