Umbilical cord blood is the blood that remains in the umbilical cord after a baby is born and the cord is cut. Until recently, this blood as well as the cord and the placenta were treated as clinical waste and were discarded. Since the discovery that cord blood is a rich source of haematopoietic stem cells and since the first transplant in 1988, this valuable source of stem cells is no longer considered as a clinical waste. Public and family banks were created to process and cryopreserve this blood for future use.
Cord blood contains all the normal elements of blood - red blood cells, white blood cells, platelets and plasma. It is also rich in haematopoietic (blood-forming) stem cells, similar to those found in bone marrow. The Haematopoietic (progenitor) stem cells are situated in the liver and spleen of every embryo. Prior to labour, these cells begin to migrate from the liver through the blood stream towards the bones for the formation of the bone marrow. Collection of cord blood can be performed either at the third stage of labour (after the birth of the baby and before the delivery of the placenta) or ex-utero (after the delivery of the placenta).
Cord blood can be used for transplantation as an alternative to bone marrow cells. Compared with adult peripheral blood or bone marrow, cord blood contains a greater proportion of highly proliferative haematopoietic progenitor cells. Most cord blood transplants have been done to treat diseases of the blood and immune system. It has also been used to restore the functional deficiencies of several genetic metabolic diseases. To date, more than 70 different diseases have been treated with cord blood transplants.
The number of transplantations using umbilical cord cells is rising every year. Since 2005 allogeneic umbilical cord transplants in children outnumber the transplantations of bone marrow cells.
The positive outcomes from cord blood research and applications have lead to new experimental applications for the treatment of other serious conditions. Scientists are investigating the possibility that stem cells in cord blood may be able to replace cells of other tissues such as nerve or heart cells.
Researchers and scientists accept that future therapies will be based on stem cells from various sources including cord blood. Research is ongoing in numerous centres for therapies of currently incurable diseases such as Multiple Sclerosis and Alzheimers'.