Stem cells in the placenta and umbilical cord are the source of platelets and the oxygen-carrying red blood cells in your bloodstream. They give birth to the immune system which fights infection and protects your body from foreign matter. Umbilical cord blood stem cells have never been exposed to the various diseases and viruses we face as we age. A single stem cell can, in theory, permanently reconstitute the entire blood-producing and immune systems.

In healthy people, stem cells continually replenish the blood and immune system cells. However, if the blood system has been ravished by disease (see diseases treated with stem cells) or by treatments such as radiation or chemotherapy, new stem cells are needed to rebuild the blood and immune systems. Preserved cord blood stem cells can be used to rebuild a person’s blood system. The stem cells you preserve could someday be used to give life to someone close to you. These stem cells are a perfect match for the donor. There is a 25 hance of finding a match between two siblings that are from the same parents. A match with a sibling offers the best hope of finding a match with another person.