Deciding whether to store cord blood

Prospective parents are often provided with information from various sources about different aspects of pregnancy, childbirth and infant care. Among them are materials about umbilical cord blood (UCB) banking for future use from commercial cord blood banks.

The tag lines of these materials are appealing, for example, "The best gift you can give your baby", "Cord blood cells may literally be life-saving to your child or family member", etc.

Some commercial cord blood banks have also periodically offered referral fees. Not only have obstetricians and midwives been approached directly by these banks, they also have to address this issue from parents who request that their baby's cord blood be collected at the time of delivery and transported for storage.

Banking an infant's cord blood has implications. This article was written with the objective of providing information for prospective parents to make an informed decision.

Umbilical cord blood

There are three types of stem cells, ie. adult stem cells, human embryonic stem cells, and induced pluripotent stem cells.

Adult stem cells are found all over the body, and can divide to form more adult stem cells or differentiate to specialised stem cells.

Human embryonic cells originate from fertilised eggs, and can develop into any specialised cell. Induced pluripotent stem cells are formed by the reprogramming of adult cells that have already differentiated into specific cells, to develop into any type of specialised cells.

The stem cells of the different tissues, and at different stages of development, vary in the number and types of cells that they can develop into. The ability of a stem cell to produce any cell type is gradually reduced as one gets older.

In short, stem cells are master cells - cells from which all other cells with specialised functions are created.

The sources of stem cells are the fertilised egg, embryonic stem cells, and adult somatic stem cells found in the blood and bone marrow, brain, neural and other tissues.

UCB contains haematopoietic stem cells (HSC), which are also found in the blood or bone marrow. However, cord blood HSC have greater proliferative and colony-forming capacities, and are more responsive to certain growth factors.

In addition, they produce fewer complications that are associated with some aspects of HSC transplantation.

Stem cell transplants

There are two types of transplants - allogeneic and autologous. Allogeneic transplants are collected from a related or unrelated donors, and transplanted into the patient after treatment of the cells.

Autologous transplants are collected from the patient before treatment, and then re-infused after treatment into the same patient.

Currently, haemopoietic stem cell transplants (HSCT) are the most established form of therapy. It involves the intravenous infusion of stem cells collected from bone marrow, peripheral blood or umbilical cord blood, to re-establish haematopoietic function in patients whose bone marrow or immune systems are damaged or defective.

It is estimated that there are about 30,000-40,000 HSCT performed annually throughout the world, and that more than 20,000 people have survived five years or more after HSCT.

HSCT is currently performed for patients with malignant and non-malignant blood disorders, solid organ tumours, and inherited metabolic and primary immunodeficiency diseases. The list of indications, hopefully, will continue to expand.

UCB can be stored for non-directed donations, directed donations in at-risk families, and directed donations in low-risk families. All donations require compatibility (HLA) matching of donors with recipients.

Non-directed donations are facilitated by the establishment of registries of bone marrow donors and UCB banks, which store the HLA data of donors and UCB. The registries and public UCB banks are involved in a global collaboration to find matches for patients worldwide.

Directed donations are carried out for some families known to have genetic diseases that can be treated with HSCT. HLA-compatible UCB of a newborn may be used for an affected sibling. If not, it may be stored for possible use by a future HLA-compatible sibling.

The use of assisted reproduction techniques to produce a "saviour sibling" is controversial, but is permitted in many developed countries. It is pertinent to know that improved chemotherapy techniques can "cure" about 80 per cent of childhood leukaemia, which is one of the main uses of related UCB banking.

The likelihood of directed donations in low-risk families is unknown. Their projected usages continue to remain speculative.

Advantages and disadvantages of UCB

Advantages and disadvantages of UCB

The advantages include faster availability, as HSCT is carried out earlier than those receiving conventional bone marrow grafts; increase in the donor pool; lower incidence and severity of rejection; lower incidence of viral transmission; and lack of donor attrition, as bone marrow donors may change their address or may not be available with the passage of time.

The disadvantages include relatively low numbers of stem cells in each UCB donation; lack of availability of subsequent stem cell donations when the HSCT fails or there is a relapse of the disease; and practical issues that may harm mother and/or baby's health, as the collection has to be done in the third stage of labour when both mother and baby require one-to-one care. This occurs if there is any alteration of the normal management of the third stage to maximise UCB collection, eg withholding controlled cord traction in the presence of a postpartum haemorrhage, or if routine maternal or neonatal observations or investigations are neglected, overlooked or delayed.

It is vital that the attending obstetrician or midwife's attention is focused on minimising adverse outcomes in the newborn and postpartum haemorrhage, and not on collecting UCB.

Some commercial UCB banks suggest that collection can be done by persons without a medical background, eg the spouse. This ignores the fact that UCB bacterial contamination rates are less with collection by experienced, trained staff, and that the adequacy of the volume collected is important.

Problems may arise, especially in Caesarean sections, when the cord is wrapped around the neck, and in deliveries of premature babies or multiple pregnancies. These difficulties are more probable in directed donations in low-risk families.

In the case of high-risk families, specific arrangements can be made to avoid harm to mother and/or baby.

In the case of altruistic non-directed donations, there is no pressure to collect UCB from any individual delivery.

Public vs private UCB banks

There is always pressure on parents to do the best for their child. While acknowledging an individual's right to autonomy, which includes the right to store UCB, it is relevant to consider the facts.

This was addressed by Eliane Gluckman et al for Eurocord, Netcord, World Marrow Donor Association (WMDA) and National Marrow Donor Program (NMDP), in their presentation "Should private banks have a role in our community" at the World Cord Blood Congress on Oct 26, 2011.

They reported that family cord blood banking from healthy siblings of patients who are candidates for allogeneic HCST (most frequent indications are haemoglobinopathies, leukaemia) are validated.

Family cord blood banking from healthy siblings of patients who are candidates for cell therapy for non-haematological diseases like diabetes and cerebral palsy are at the research stage. In the case of family cord blood banking from healthy infants without any known familial pathology, there is no indication of autologous transplant for haematological diseases except in the case of gene therapy.

The indications for non-haematological diseases are being investigated in research protocols.

The researchers pointed out that there are few isolated cases of autologous cord blood transplant for haematological diseases reported in journals, although they are advertised by private banks marketing autologous storage.

In addition, informed consent and quality control are unknown, and the indications are very limited, with the probability of use in paediatrics of four out of one million units of UCB stored.

They stated that there is misleading information in that the service sold currently has no real use; there is failure to differentiate between unrelated and autologous HSCT; there is no clarification that current clinical research in regenerative medicine uses bone marrow or blood cells; there is over-interpretation of basic stem cell research data, and that such advances in research are used to promote autologous UCB storage.

The researchers also stated that the benefits of public banks are proven. They are quality assurance by accreditation; non-profit; guarantee of continuity; solidarity; equal access; balanced information; and a global inventory.

On the other hand, the benefits of private banks are unproven. Quality is variable. It is for profit, and continuity is not guaranteed. There is unequal access, biased information and no inventory.

The European Commission's Group on Ethics in Science and New Technologies report on the ethics of private umbilical cord banking stated: "The legitimacy of commercial cord blood banks for autologous use should be questioned as they sell a service, which has presently, no real use regarding therapeutic options. Thus, they promise more than they can deliver. The activities of such banks raise serious ethical criticisms.

"If commercial banks are allowed (in any EU member state), appropriate information should be given to consumers willing to use their services, including the fact that the likelihood that samples may be used to treat one's child is currently negligible, that future therapeutic possibilities are of a very hypothetical nature, and that up until now, there is no indication that the present research will lead to specific therapeutic applications on one's own cord blood cells."

The Royal College of Obstetricians and Gynaecologists (RCOG) of the United Kingdom stated: "The RCOG strongly supports the concept of a NHS Cord Blood Bank for allogeneic storage of donated cord blood and would like to see it well funded. However, it remains unconvinced of the benefit of personal commercial banking for low-risk families."

The Society of Obstetricians and Gynaecologists of Canada stated: "Collection and long-term storage of umbilical cord blood for autologous donation is not recommended because of the limited indications and lack of scientific evidence to support the practice. Commercial cord blood banks should be carefully regulated to ensure that promotion and pricing practices are fair, financial relationships are transparent, banked cord blood is stored and used according to approved standards, and parents and care providers understand the differences between autologous versus allogeneic donations, and private versus public banks."

The Health Ministry requires that "the establishment of public and private cord blood banks be in accordance with national standards and guidelines", and subject to its licensing under the Private Health Care Facilities and Services Act. It requires all UCB banks to comply with its standards on collection, storage and infusion of HSC.

The ministry also recommends that "indications which are experimental and promising, eg for tissue repair and revascularisation, shall be studied further in the context of clinical trials."

While much has been achieved, there is still an enormous amount of scientific work that needs to be done to realise the potential of stem cell therapy from the laboratory into clinical practice.

When there are limited or no options in the treatment of certain chronic or terminal conditions, hope can be an addictive drug. Doctors and regulators have the task of tempering hope with realism.

It would be prudent for all prospective parents and patients to seek advice from their doctors about the scientific basis of UCB banking, the implications of collection, the dilemma between personal and altruistic cord blood storage, and the likely usage of the stored cord blood.

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