Cord blood is the blood left in the placenta and umbilical cord after delivery of a baby. Like bone marrow, it is a rich source of special cells called stem cells. These cells have the ability to renew themselves and then convert themselves into all the various cell types found in blood. This means that cord blood, like bone marrow, can be a rich source of cells for transplantation. For some patients with leukemia or other blood disorders such as aplastic anemia, transplantation offers the only chance for long-term survival.
Cord blood can also be used to replace normal stem cells destroyed by aggressive treatment of metastatic cancer (cancer that has spread from its place of origin to other parts of the body). In the future, it may even be used in the treatment of some diseases of the immune system, including AIDS.
Cord blood banks have been established in a variety of centres across North America. Some of these banks rely on donations of cord blood, just as the Canadian Blood Services relies on blood given by anonymous donors. Some private cord blood banks charge a fee to parents to maintain their child’s cord blood in case the child or a relative develops a need for transplantation. In western Canada, cord blood banks have been established in Vancouver and Edmonton.
The first successful cord blood transplant was done in 1988. The patient was the older brother of the donor. The first transplant with an unrelated donor was in 1993.
What is the value of cord blood collection?
Cord blood appears to offer some distinct advantages over bone marrow as a source of cell transplantation.
These advantages of less risk, potential for a large and diverse donor pool, better chance of finding a match, and a better chance of successful transplantation using cord blood cells are strong reasons for storing cord blood.
How is cord blood collected?
Collection of the cord blood is painless, with no risk to either mother or baby.
Cord blood can be collected in one of several different ways. Once the baby is delivered, and while the placenta is still in the mother’s uterus, blood can be collected from the cord. Usually a small amount of blood is removed from the cord to check that the blood types of mother and baby are compatible. Sometimes another test is done looking for any evidence the baby had trouble with oxygen delivery in labour. After the standard tests are collected (all of which are painless), a sample of blood can be collected for cord blood banking.
The cord is thoroughly cleansed to removed any traces of the mother’s blood and decrease the chance of ruining the sample by contamination. Collection is done with a large syringe or by putting a small tube into the largest vessel in the cord. This tube is then connected to a blood donor bag. The bag is placed on the floor to allow the blood to drain by gravity into the bag. Usually about 70 cc of blood is collected: a minimum of 40 cc is required for transplantation for a child, more for an adult.
Alternatively, the blood can be obtained after the placenta is delivered. This is slower and technically more difficult. Collection with the placenta still in the uterus takes about 5 to 10 minutes.
Once the sample is collected, it must be kept at room temperature during transportation to the banking facility. Processing of the sample is done within 48 hours of collection. During that 48 hours, blood samples are obtained from the mother to screen for Hepatitis B and C, HIV, and syphilis. The blood is treated to extract the stem cells, which are then frozen. In cases where the cord blood is given as a donation, the cells are then available for the treatment of any tissue-matched patient in need.
Cord blood banking is in its infancy, but shows great promise to improve the outlook for patients requiring transplantation. If you are expecting a baby, consider making a cord blood donation. Talk with your caregiver to find out if the facility where you plan to deliver has arrangements with a cord blood bank for the collection and transportation of samples.
Collection is simple, painless and cost effective. Up to 10,000 samples can be stored in a single liquid nitrogen freezer. The more cord blood donated, the more likely that a match will be found for the patient whose only chance of survival is transplantation. It may be that the birth of your child is not just the beginning of a new life, but the saving of another.