Midgut volvulus with hemorrhagic ascites: a rare cause of fetal anemia.

Fetal intestinal volvulus is a rare life-threatening condition usually manifesting after birth. It appears on prenatal ultrasound imaging as a twisting of the bowel loops around the mesenteric artery, leading to mechanical obstruction and ischemic necrosis of the bowel. Vascular compromise can result in bowel infarction and eventual perforation of the necrotic bowel, with the development of hemorrhagic fetal ascites and fetal anemia. We report a case of intrauterine midgut volvulus, suspected when ultrasound imaging revealed dilated bowel loops at 31 weeks' gestation, with fetal anemia also suspected on measurement of increased middle cerebral artery peak systolic velocity by Doppler ultrasound examination. Volvulus should be considered in the differential diagnosis when ultrasound imaging demonstrates dilated loops of bowel, especially in association with fetal ascites.