Cord blood banking – the facts
The full reference for this draft article is: Trotter S (2008). Cord blood banking: the facts. Midwives – the magazine of the RCM; Aug/Sept: 30-31. Original article written for The RCM Journal - June 2008
Click on the links below to go to the different sections:
Introduction
In January this year the Prime Minister Gordon Brown’s speech on health screening within the National Health Service [NHS] (BBC 2008) heralded its forthcoming 60th anniversary as a “great institution with healthcare still free at the point of need”.
Changes in the way the NHS provides such a service continue to evolve as new areas of diagnosis, treatment and the potential for further scientific advances become a reality. One such area is cord blood banking.
The nature and uniqueness of cord blood as a source of stem cells is no longer in dispute. The implications for midwifery practice and the associated legislation has been covered in a recent paper by the author (Trotter 2008). The subject of cord blood, its safe collection and potential uses continues to stimulate discussion within midwifery. In addition media interest in cord blood banking highlighting its potential benefits in life-saving or life-preserving applications has become more common.
While the author aims to provide midwives with a summary of this complex subject, in-depth analyses of the political or ethical issues surrounding this topic are beyond the scope of this article.
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Cord blood – a brief history
It was in the early nineteen seventies that Ende (1995) first observed that cord blood, like bone marrow, was a rich source of Haematopoietic Stem Cells HSCs. These are Master cells with the capacity to become any type of cell or tissue (pluripotent). In an embryo these stem cells are known as True Stem Cells (TSC) in that they retain an unlimited capacity for self renewal whereas adult stem cells could be better described as Progenitor Cells (PC) as their capacity for unlimited renewal has not been conclusively demonstrated.
The four main sources of stem cells are: embryonic blood, peripheral blood, bone marrow and cord blood. Understandably, the use of embryos to harvest stem cells is highly emotive and while Bone Marrow Transplants and [cytokinine mobilised] Peripheral Blood Stem Cells (PBSC) work well, Umbilical Cord Blood Transplantation (UCBT) has been demonstrated to be equally useful (Arcese et al 2006).
The first successful UCBT was carried out in 1989 (Gluckman et al 2004) confirming UCB as an important and viable source of HSC. There have been thousands more successful transplants since then (for various reasons including malignancies of the blood in children and more recently adults). Where the use of cord blood has become common practice, the number of Cord Blood Banks (CBB) worldwide has continued to increase with the development of many centres of excellence. Cord blood may have many potential uses. It has been postulated that stem cells could be used in the treatment and research of diseases such as diabetes, Parkinson’s, regeneration of heart muscle and Alzheimer’s (Edozien 2006). [back to top]
UCB – collection and storage
UCB can be collected either in-utero (before separation of the placenta) or ex-utero (following complete expulsion of the placenta). Both methods are straightforward to perform following appropriate training (similar to taking cord blood for routine samples if a woman is rhesus negative). It has been postulated that in-utero collection is quicker (two to five minutes against 10 to 15 minutes for ex-utero collection), easier to perform and results in a larger volume of collected blood (Lasky et al 2002) while others believe there is no significant difference (Warwick 2004). Whichever method is used, infection control is vital to prevent contamination from bacteria, fungi and maternal blood or secretions.
Fastidious pre-cleaning of the cord is carried out prior to cannulation. Passive blood flow into specialised bags containing anticoagulant usually results in an average volume of 60 to 80mls.
Once collected, the cord blood is processed in a closed system to remove the red blood cells and plasma, leaving a buffy coat (white blood cells and platelets left after the separation process) of 20 to 30mls maintaining the quality and quantity of stem/proginator cells.
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Concerns from the RCM and RCOG
The last position paper on CBB from the Royal College of Midwives (RCM) was issued in 2002 (RCM 2002). This advice remained unchanged following a press release in 2007 (RCM 2007). While it supports the collection of UCB when medically indicated, it does not support the commercial (private) collection of UCB. Concerns include:
- the possibility of future litigation due to problems during collection, storage and transportation (disclaimers are now in place to address these issues)
- the potential for increased risk of needle stick injury (already a calculated risk during the intrapartum period, this additional procedure could be seen to increase exposure)
- the need for more evidence to demonstrate real value of the collection of UCB (there is considerably more evidence today than when this position paper was published - examples of such evidence is reviewed by Trotter [2008])
- the possibility of disruption around the time of delivery (this could be addressed by the introduction of standard guidelines implemented within each maternity unit to safeguard mother and baby)
- the need for wider debate in the NHS on the ethical, legal and safety implications of introducing commercial initiatives (National Institute for Clinical Excellence [NICE] guidelines could also be developed to take account of these issues)
Recent developments
The Human Tissue Authority (HTA) announced new rules on April 30th 2008 for cord blood collection. From July 5th all maternity units that collect cord blood will need to act under the HTA license to ensure:
- staff have training in collecting cord blood, raising standards and making sure the sample is the best quality possible
- procedures which will help prevent any medical attention being drawn away mother or child
- a system is in place to make sure the cord blood cells are traceable from collection to use (HTA 2008).
In the most recent amendment to the Human Fertilisation and Embryology Bill (DoH 2008 and BBC 2008a) The House of Commons voted to allow limited research using human/animal embryos and the go-ahead for the creation of ‘saviour siblings’ (conceived to help an ill relative).
The case of a two year old toddler in need of a stem cell transplant (for leukaemia) that had failed to respond to conventional treatment was recently highlighted in the British press (Beatson 2008). Fortuitously these parents had taken the decision to collect cord blood from their younger baby, which has since been shown to be a perfect match for his sister. Plans are underway to carry out an umbilical cord blood transplant (UCBT) in the near future which it is hoped will provide a cure.
Such procedures would have seemed impossible just a few years ago but there is no reason why this form of stem cell transplant should not become commonplace in the future. [back to top]
The way forward
As awareness of CBB becomes more widespread an increasing number of parents will come forward to ask about cord blood collection. This precious resource which, up till now has been discarded, can be stored in private banks as a potential autologous (for use by the donor) or allogeneic (for use by a family member) donation. While there has been opposition to the former type of donation, due to the apparent low odds of it ever being needed (1:2700 by the time a child is 18 years old - Johnson 1997) others have welcomed more altruistic ways of donating cord blood (Fisk 2008).
It is fair to say that resources within the NHS, especially in maternity units, are over-stretched as it is and the introduction of any service, except for ‘at risk’ cases, could be seen as unnecessary, without proven benefits. However parents have a right to expect a realistic explanation of the pros and cons associated with cord blood collection (Edozien 2006) so they can make an informed choice. This can only be offered when local and national guidelines are in place.
Whatever happens there is a need for ongoing debate and discussion between the companies providing this innovative service and the maternity units where collection is carried out. As midwives, we will then be better prepared to answer the inevitable questions posed by parents. [back to top]
