Prenatal ultrasound assessment and fetal heart monitoring: analysis of dizygotic twins discordant for body stalk anomaly in the third trimester of pregnancy.

We describe a case of dizygotic twin pregnancy which was referred to our centre because of a discordant anomaly of one of the twins. The ultrasound examination revealed a large extra-abdominal mass (liver and bowel) with micromelia, severe kyphoscoliosis and a short umbilical cord of the second dizygotic discordant twin. These ultrasound findings were diagnosed as body stalk anomaly. Body stalk anomaly in twins is extremely rare. This is, to our knowledge, one of the few documented cases reported on dizygotic twins discordant for this anomaly. This finding, in association with a decrease of amniotic fluid volume, may be attributed to early amniotic membrane rupture as the primary event in the pathogenesis of body stalk anomaly.