Before a baby is born he is connected to his mother
by the umbilical cord and placenta. They allow nutrients to flow
from the mother into the baby. After a baby is born his umbilical
cord is cut and he is detached from the mother. The remaining
umbilical cord and placenta, called the afterbirth, is expelled
from the mothers body minutes after the baby is born. Usually
the doctors and nurses throw it away. However, there is blood
left in the umbilical cord and placenta, and this blood can be
collected and used to help someone. It is called cord blood.