Umbilical cord blood is the blood that remains in the umbilical cord and placenta following birth and after the cord is cut. Cord blood is collected because it contains stem cells which are genetically unique to the baby and his/her family. However, cord blood has its limitation and can only be used generally for the treatment of blood and immune system disorders. Umbilical cord blood contains only stem cells of blood, immune system and a very limited amount of mesenchymal cells but of no other organ systems of the body. For that reason, diseases of central nervous system, digestive system, excretory system, respiratory system, genetic and chromosomal diseases, etc. cannot be treated with success by umbilical cord blood stem cells. It is rather impossible that the only two cell types out of the 200-220 cell types present in our bodies can turn into stem cell of every organ or tissue.

Although the potential use of umbilical cord blood is expanding rapidly, the odds that family members without a defined risk will need to use their child's umbilical cord blood are low. Cord blood contains only a limited amount of stem cells which may not be sufficient for an adult usage. Will umbilical cord blood be of guarantee a match for family members or siblings? It is still uncertain. Hence, umbilical cord blood stem cells will not guarantee suitable treatment for all inherited genetic diseases.