Cesarean section scar as a cause of abnormal vaginal bleeding: Diagnosis by sonohysterography

A previously undescribed cause of abnormal uterine bleeding is presented. N ine of 310 women evaluated by sonohysterography for abnormal bleeding demon strated an 8 to 17 mm gap in the anterior lower uterine segment myometrium at the site of prior cesarean deliveries. All women were premenopausal and had a history of 2 to 12 days of postmenstrual spotting. Presumably a lack of coordinated muscular contractions occurs around the cesarean scar, allow ing the defect to collect menstrual debris. Subsequently, the debris leache s out through the cen iu for several days after the majority of menstrual f low has ceased.