Cord blood is collected from the umbilical cord after the baby is born and after the cord has been cut and clamped by the doctor. The doctor’s first concern is to mother and baby and once everything is ok here, then the doctor will take the blood.
Cord blood can only be collected from the umbilical cord and placenta for a short period following the birth, once the cord has been clamped and the placenta delivered. It has to be achieved before the clotting reactions make blood collection impossible.