Expert Comment: Delayed Cord-Clamping in ChildbirthTuesday 21 May 2013
Dr Denise Roche, Senior Lecturer in Exercise Physiology at Liverpool Hope, recently appeared on BBC breakfast talking as a mother and strong advocate of delayed cord-clamping in childbirth. Here, she examines the virtues of delayed-clamping from a health perspective.
The practice of immediate cord-clamping in childbirth, which has been standard NHS practice in England since the 1960s, is currently under review as increasing amounts of research evidence challenges the necessity and consequences of such archaic intervention during third-stage labour.
The National Childbirth Trust and other prominent bodies recognise that delaying umbilical cord-clamping once an infant has been delivered, for as little as 30 seconds to whenever the cord stops pulsating, can provide the new-born with vital placental blood which increases the blood volume of the newborn by 32%. The net effects of delayed clamping are enhanced levels of circulating haemoglobin and, by association, a boost in oxygen levels and iron stores, the latter which may last up to six months. Immediate cord-clamping, on the other hand, is becoming more widely acknowledged as not being the best practice for full-term, uncomplicated births. One physiological drawback of immediate-clamping is that it may pose a health risk to infants through increasing the likelihood of iron deficiency. Iron deficiency is most likely pre-school infants and children (aged 0-5 years) due to the rapid expansion of the red-cell mass and substantial iron requirements needed by the rapidly growing tissues during infancy and childhood. Iron deficiency and Iron-deficiency-anaemia, may actually harm a child’s brain development and are linked with delayed cognitive and psychomotor development and possibly behavioural problems and sub-optimal physical development.
Due to the risks of iron-deficiency in causing neurodevelopmental delay, the World Health Organisation dropped the outdated policy of early cord-clamping some years ago. They state “Early cord clamping (less than one minute after birth) is not recommended unless the neonate is asphyxiated and needs to be moved immediately for resuscitation.” Despite the clear message of support for delayed-cord clamping by the WHO, there still exist discrepancies in policies and practice across the UK as we try to catch up with other international advocates such as Australia. As such, the National Institute for Health and Care Excellence (NICE), who inform and govern NHS policy on best practise, and the Royal College of Midwives are currently reviewing and updating their guidelines (UK) on when to clamp the umbilical cord after a baby is born. It is anticipated that their new guidelines, due to be published in 2014, will corroborate the recently modified guidelines of the Royal College of Obstetricians and Gynaecologists (UK), that support and advocate delayed cord-clamping. New guidelines are long overdue considering the mounting evidence from highly regarded and influential sources including the Cochrane Library and the BMJ on the numerous physiological benefits attributable to delaying clamping that outweigh both maternal and infant risks.
The Cochrane Review on delayed cord-clamping provides a very encouraging range of findings with no maternal or neonatal adverse outcomes being established through their review of studies comparing delayed-clamping to the older method of immediate-clamping. Significantly superior newborn haemoglobin levels were established in delayed - as oppose to immediate - clamping, plus less anaemia was reported in neonates at 6 hours and 24-48 hours post-birth with delayed-clamping
The value of permitting the completion or part-completion of the placental transfusion, depending on how long the delay in clamping is. This potential extra blood volume ordinarily remains in the placenta (and is wasted) once the baby is born with immediate cord-clamping. Delayed-clamping gives an immediate boost to the circulation of the newborn and eases, supports and elongates the transition between placental to independent pulmonary respiration in the newborn. It is a natural and entirely physiological way that infants may get off to the best possible start in life as they make cardiopulmonary adaptations to conditions outside the womb.
It appears ridiculously illogical to immediately sever the cord that has supported and nourished the foetus for the past 40 weeks in utero when that cord still has so much more to offer. As an Exercise Physiologist, I make analogies from my own research and teaching expertise in sport performance and health. Delayed cord-clamping proffers many of the benefits to that of exercise training that athletes and the general population may strive to attain, but, in a much more crucial time-period i.e. the first few minutes of life. Delayed cord-clamping gives an immediate boost to the circulation of newborns; the baby can gain up to a third more blood volume and a 60% higher red blood-cell count. This means that, like an athlete, the newborn has a greater capacity for carrying oxygen and delivering it to cells that need it. In newborns, this includes the all-important brain tissue and central and peripheral organs including the skin. Athletes for decades have attempted to mimic what occurs naturally with delayed cord-clamping, by using EPO (Erythropoietin) and blood doping techniques to attain a circulatory boost for enhanced performance. Delayed-clamping also causes an increase in the infant’s plasma volume as a direct result of permitting the placental transfusion. Such an increase in plasma volume, another aim of endurance training, helps augment cardiac output, the amount of blood ejected from the heart per minute, meaning the heart has to work less hard for a more efficient output.
Adequate blood volume and flow and the correct functioning of vessels are pivotal to maintain circulatory health and optimal performance. We already know that chronic disease processes such as atherosclerosis begin in childhood and are influenced by not just maternal behaviours, but ante-natal and peri-natal factors. Ways at reducing in childhood the likelihood and progression of vascular disease in adult years through lifestyle intervention such as exercise is a focus of my research. I hope that in the near future, the longer-term benefits of delayed cord-clamping on paediatric circulatory health may be an area of research focus by the School of Health Sciences, building on her own and her colleagues’ research interests in blood flow and cardiovascular physiology.