P50: Fetal blood loss

P50.5: Fetal blood loss from cut end of co-twin's cord

The placenta forms in the mother’s womb during pregnancy. The placenta consists of cells from the mother and cells from the unborn child. The umbilical cord connects the child to the placenta. During pregnancy the umbilical cord connects the child's blood circulation to the mother's. The child receives nutrients and oxygen via the blood vessels in the umbilical cord.

With a multiple pregnancy, the children's blood circulation systems can get connected to one another. This happens if the children share a single placenta. When one of the children is born, its umbilical cord is cut. Then the unborn child may lose blood via the severed umbilical cord of the child that has been born. The affected child can then lose blood. The affected child may then no longer get enough oxygen.