A case of uterine rupture diagnosed based on routine focused assessment with sonography for obstetrics.

The patient was a 38-year-old primigravida woman with a previous history of myomectomy via laparotomy. At 30 weeks of gestation, she visited our emergency center because of sudden severe abdominal pain. Routine focused assessment with sonography for obstetrics (FASO) indicated no echo-free space at Douglas' pouch or between the spleen and kidney; however, echo-free spaces were visualized around the intestinal tract and at Morrison's pouch. Therefore, a diagnosis of hemoperitoneum due to uterine rupture was suspected, and emergency cesarean section was planned. During surgery, a small defect of the myometrium was found on the posterior to fundal uterine wall, with bleeding from the defect. We believe that routine FASO is useful for detecting emergency conditions, including uterine rupture during pregnancy and postpartum. When a pregnant woman complains of abdominal pain, an assessment with FASO is strongly recommended in the daily clinical setting.