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A sterile needle

A sterile needle pierces the umbilical cord, still attached to both the baby and the undelivered placenta. Umbilical cord blood flows into the hollow needle and into a collection bag. The process is completely painless. Cord blood contains a higher percentage of stem cells than peripheral blood. Cord blood is either collected with the placenta in utero, before the blood has a chance to clot, or after the placenta has been delivered, so that the placenta can be manipulated to maximize the amount of blood collected.