A disadvantage of cesarean section en caul: Umbilical velamentous insertion, a risk factor and proposed mechanism of neonatal anemia.

Cesarean section en caul could cause neonatal anemia, but the mechanism remains unknown. We demonstrate an association between neonatal anemia and velamentous insertion of the umbilical cord in cesarean section en caul, and suggest a way to make this procedure safer. We performed cesarean section en caul, but the placenta and the membrane sac were delivered separately. The neonate was severely anemic. The umbilical cord was attached to the membrane and the blood vessel connecting the umbilical cord and placenta was torn. The amniotic membrane covering the placental surface had peeled away. Velamentous insertion of the umbilical cord could be a cause of neonatal anemia associated with cesarean section en caul.