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The placenta, umbilical cord and the blood within it are very important in pregnancy. However, the blood serves no purpose after delivery if it is discarded. The blood can be collected after delivery with no risk to the baby or mother. These blood stem cells (BSC) are proven to be useful in the treatment of many blood disorders and cancers.
What is cord blood banking?
Blood stem cells (BSC) from cord blood can be harvested from the umbilical cord after delivery of your baby and clamping of the cord. A small needle is inserted into the umbilical cord after adequate sterilisation for this purpose.
The cord blood with the BSC is then drawn out (Figure 42.1). This process will not hurt you or your baby.
The cord blood is processed in the laboratory where a specific layer of cells containing the BSC will be extracted. A cryopreservative is then added to the cord blood before placing it in liquid nitrogen tanks at approximately –180 degrees Celsius.
 What are blood stem cells?
BSC are immature cells that are found in the bone marrow and peripheral circulation of an adult. The blood of the umbilical cord (cord blood) also contains large amounts of these cells. They can grow and mature into red cells, white cells and platelets.
BSC are different from embryonic stem cells. There are no ethical issues with BSC as no one is harmed with the harvesting of BSC from the umbilical cord. In fact, these BSC will become waste products if they are not harvested and stored.
Why are BSCs so important and useful?
Since the 1960s, BSC has been used for stem cell transplants (SCT), called Bone Marrow Transplant (BMT) in the past as BSC were harvested from bone marrow. This treatment can potentially cure many diseases, especially blood cancers.
 Unfortunately, many patients who require SCT do not have these BSCs. These BSCs are usually obtained from a matched sibling. However, many patients are from single child families (hence, no possible sibling donor) or from families in which the siblings do not match. As a result, many of these patients die.
Can we use blood stem cells from anyone?
HLA or Human Leukocyte Antigen refers to the protein structures on white cells. These proteins are responsible for rejecting or accepting foreign cells. HLA is determined by the genes of both parents. Hence parents and child will only be half matched and the best chance of a match will usually be from one of the siblings. The larger the family size, the better the chance of finding a match.
The success of SCT depends on HLA-matching. Graft rejection may occur from a HLA mismatch. Fortunately, BSC from cord blood is slightly different and can tolerate some mismatching.
The importance of having HLA-matched BSC led to the development of Bone Marrow Donor Registries from unrelated, voluntary donors in the 1980s. These registries help desperate patients find HLA-matched donors necessary for life-saving stem cell transplants. The first such registry was the Anthony Nolan Registry in the United Kingdom. It was set up by the parents of Anthony Nolan who died of leukaemia because he could not find a matched donor.
What is private cord blood banking?
Private cord blood banks started in the mid-1990s as knowledge of the usefulness of BSC became widespread. Individuals who appreciated the value of BSC wanted to store these BSC from their child’s cord blood for their own use.
This is especially relevant for families who are planning to have one child or a small family, late pregnancies, and those from mixed marriages. In these families, it may be difficult to find a HLA-matched donor.
Indeed, using your own BSC for SCT may be preferred for some diseases while in other diseases, such as leukaemia, it is better to use a matched sibling’s BSC.
What is public cord blood banking?
The first umbilical cord blood transplant was performed in 1989 after cord blood was shown to contain large amounts of BSC. Following this success, public cord blood banks developed across America and Europe and in Singapore, the Singapore Cord Blood Bank was established. Cord blood is harvested from voluntary pregnant women at delivery. The BSCs are then extracted, frozen and stored. Patients who require a SCT but do not have a donor can then search these cord blood banks for a HLA-matched donor. However, as BSC from cord blood can tolerate some mismatches, it is easier to find a “usable” donor in public cord blood banks.
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