Umbilical stem cells
An alternative source to obtaining stem cells
Many of the embryonic stem cells used in research in the UK come from fertilised eggs donated by people undergoing in vitro fertilisation (IVF). They decide how any ‘excess’ embryos from these procedures are used and can choose to donate them to research. The use of embryonic stem cells is controversial, and opponents argue that destroying embryos to remove stem cells is inhumane. Using umbilical cord stem cells is an alternative source, potentially with fewer ethical concerns.
In 1978, blood stem cells were discovered in human umbilical cord blood. At first it was thought that cord blood stem cells were only able to differentiate into types of blood cell, but research now suggests that they contain haematopoietic (blood) stem cells (HSCs), which are normally only found in the bone marrow. These stem cells are able to become all types of blood cells – cord blood stem cell transplants have been used to help people with diseases such as leukaemia and lymphoma.
However, if the donor and the recipient are not genetically similar enough then the patient can reject donor cord blood, although this is less likely to happen than during bone marrow transplants.
The umbilical cord contains considerably less HSCs than bone marrow, which can make it difficult to treat adults with these stem cells. However, more and more blood stem cell banks are being set up, which will make HSC donation a more viable option for adults and increase the chance of patients finding a suitable donor match.
Questions for discussion
- Should it become obligatory for women who give birth to donate their umbilical cord blood for research?