22 November 2010
ByAppeared in BioNews 585
The article recalled how doctors had reinfused Dallas' own umbilical cord blood (UCB) cells. His parents had them saved at birth and stored in a private cord blood bank 'just in case' they were needed. It appears they were right to do so - Dallas transformed from being unable to crawl, sit, walk or suck to walking, reaching and saying 'moma' within five days of the treatment. This remarkable achievement prompted his parents to call cord blood stem cells 'liquid gold' (2).
Dallas - it seems - is not alone. This week, the media reported on a British girl, Sasha Browne, who also suffers from cerebral palsy. Her stem cells were banked at birth with private company Smart Cells and - like Dallas - had her cells reintroduced into her body. Sasha, it is reported, has also shown signs of improvement to her motor skills. Her physiotherapist reportedly declared her progress 'had been faster than that of her other patients with the condition' (3).
A quick search in Google reveals many more children with similar stories - Ryan Schneider, Chloe Levine, Abby Pell, Jack Abernathy, Antony Orjuela and Hayleigh Cox to name but a few. Many grace the websites of private cord blood companies eager to tell their story to other families. But what these children have in common - besides having their cord blood saved at birth - is they all have cerebral palsy or anoxic brain injury. This begs the question: 'Is there a connection between saving a child's cord blood and developing neurological problems?'
To save the optimum cord blood volume for reinfusement, the baby's umbilical cord must be clamped before the cord has ceased pulsating (4) (5). Early clamping, however, can prevent full placental transfusion. This transfer of fetal blood from the placenta at birth provides the baby with up to 30 percent more blood volume and up to 60 percent more red blood cells (6).
An animal study has revealed blood loss at birth could result in harm (7). In the study, 25 percent of the blood volume of newborn rats was removed. At only three hours old, proinflammatory cytokines, indicating tissue damage, were detected in the lungs and liver of the rats whose blood was removed. No proinflammatory cytokines were detected in rats subject to no intervention at birth. The researchers concluded removing the rat pups' blood had damaged their vital organs.
These results show early cord clamping to procure cord blood may interfere with placental transfusion, which may deny the human infant of up to 30 percent of its total blood volume. Given the effects of blood removal in animals, any denial of blood volume can present a risk to the health of the baby.
Dr Judith Mercer from the University of Rhode Island says about immediate clamping: 'In our well-intended haste to transfer an infant to the paediatric staff, we may be denying the infant a significant part of his vital blood supply' (8). A study published in 1998 further showed high quantities of proinflammatory cytokines were present in early blood samples taken from newborn infants who later developed cerebral palsy (9). Their presence suggests early clamping for UCB collection may pose health problems for the baby.
The risk of Intraventricular Haemorrhage (IVH) (10) in preterm infants is also a reported complication of early cord clamping. IVH is a serious condition, which can ultimately lead to brain damage. A study of 38 women who had preterm deliveries in South Africa in 1988 (11) found 78 percent of those whose cords were clamped early experienced IVH compared to 35 percent of those delayed for up to one minute.
The principal investigators in the South African study suggested IVH occurs due to the sudden increase in pressure to the arteries caused by immediate clamping, which prematurely cuts off the blood supply (12). The research, however, has attracted criticisms due to the sample size, the study location and the fact its participants were not candidates for cord blood collection (13).
Only scientific statistical information can link the timing of cord clamping with the possible risks saving cord blood may generate. The dearth of valid data adds to the uncertainties of the risks involved. While cerebral palsy and birth-related brain injury can be caused by several different factors, the time has come to conclusively exclude cord blood collection as a potential cause. We owe this to parents desperate to safeguard their children's future health, but who may be placing them at greater risk.
If nothing else, awareness must be raised for those who do participate in cord blood collection. We need to ensure their private cord blood provider adopts the delayed cord clamping method as advocated by public cord blood banks and those who collect for at-risk families.
I'll leave the final word to consultant obstetrician and gynaecologist, David Hutcheon, who said: 'Cord blood collection must not be allowed to restrict the [delayed cord clamping] practice. The value of delayed cord clamping has been shown whereas the value of commercial cord blood banking is still hypothetical at present' (14).