Comment
In 2012, WHO updated its 2006 report on basic neonatal resuscitation and recommended delayed umbilical cord clamping for 1 to 3 min after birth, with the infant held at or below the level of the placenta.1 40 years of accumulated evidence supports this strategy, which increases iron stores and reduces the risk of iron deficiency anaemia in infants, a major global health benefit.2 For preterm infants, the practice reduces the rates of intraventricular haemorrhage by up to 50%.3 Because even mild intraventricular haemorrhage increases the risk for neurocognitive deficits, cerebral palsy, and developmental delay,4 the effect of delayed cord clamping for all infants could be huge. Therefore, many professional societies worldwide have issued similar guidelines, albeit with minor variations.5,6 But introduction of delayed cord clamping into practice has been sporadic,7,8 with logistical issues being one possible reason. Intuitively, to keep the newborn baby’s position below the level of the placenta in situ should maximise the volume of placental transfusion. However, trying to hold on to a wet, vigorously crying, and wriggling infant at the perineum for 2 min, in gloved hands, is awkward and can be risky. When the mother is waiting anxiously to hold her baby and the father is taking photographs, 2 min could seem like an eternity. The study by Nestor Vain and colleagues9 in The Lancet should bring a sigh of relief from those trying to incorporate delayed umbilical cord clamping into practice. The investigators randomly assigned 197 healthy term newborn babies to be held at vaginal level for 2 min after birth, and 194 infants to be placed on the maternal chest or abdomen for 2 min, after which the umbilical cord was clamped. With an elegant, time-tested method,10 investigators assessed placental transfusion by weighing the newborn baby soon after birth and again at 2 min, just after cord clamping. The results are convincing and show that gravity did not have an effect on volume of placental transfusion. The increase in mean weight was nearly identical between the groups; for newborn babies held at the level of the vaginal introitus, the mean weight gain was 56 g (SD 47; 95% CI 50–63), and, for those placed on their mother’s chest or abdomen, was 53 g (45; 46–59); difference 3 g (95% CI –5·8 to 12). Because 1 mL of blood weighs 1·05 grams, the estimated average volume
of placental transfusion was 50–53 mL, or about 14–15 mL/kg for an infant who weighs 3·5 kg at birth. The importance of this study should be viewed in the context of the long and convoluted history of the debate on cord clamping.2,3,5 Despite strong evidence for its benefits, and even after many systematic and scholarly reviews, editorials, and letters to editors, compliance in use of delayed cord clamping is poor; a postal survey in the UK found that for term births 74% of obstetricians and 41% of midwives clamp the cord within 20 s, and for preterm births the frequencies were 57% and 55%, respectively.8 So, where is the rub? Hutchon7 writes that instead of rushing to implement this practice, too often obstetricians and midwives rush to cut the cord, perhaps because they are unaware of the present evidence, or because of pragmatism and conflicting guidelines. Many do not realise that immediate cord clamping is an intervention, probably incorporated without proven benefits, into protocols on active management of the third stage of labour. Might there also be some reluctance because of the competing commercial interest in collection of cord blood for banking? The study by Vain and coworkers9 does not resolve all issues associated with this practice. The researchers recruited only vaginally-delivered healthy term infants— not caesarean births or preterm infants—and they excluded those requiring resuscitation. More research should be done to address these issues. Moreover, Vain and colleagues found a large variation between centres in weight gain at 2 min of age. They ascribe this finding to possible variations in the use of epidural anaesthetics that might change uterine activity, the timing of oxytocin administration in relation to birth, and to differences in the time of first weight measurements in relation to post-partum uterine contractions. As the practice becomes more widespread, new issues might emerge about the logistics of delayed cord clamping in modern obstetric practice. Some of these could include resuscitation with an unclamped umbilical cord, the optimum interval between delivery and cord clamping (does this vary by gestational age?), maternal or fetal haemorrhage, multifetal gestations, and fetal polycythaemia. Nevertheless, all questions might not have to be answered before pragmatic protocols are
www.thelancet.com Published online April 17, 2014 http://dx.doi.org/10.1016/S0140-6736(14)60411-6
Science Photo Library
Delayed cord clamping: does gravity matter?
Published Online April 17, 2014 http://dx.doi.org/10.1016/ S0140-6736(14)60411-6 See Online/Articles http://dx.doi.org/10.1016/ S0140-6736(14)60197-5
1
Comment
developed to incorporate this physiologically sound11 and immensely beneficial procedure into obstetric practice, and offer it to most, if not all, newborn infants.
4
Tonse N K Raju
6
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA [email protected] I declare that I have no competing interests. The opinions expressed here are those of the author and do not necessarily reflect those of the US National Institutes of Health or Department of Health and Human Services. 1 2
3
2
WHO. Guidelines on basic newborn resuscitation. 2012. Geneva, Switzerland: World Health Organization, 2012. McDonald SJ, Middleton P, Dowswell T, Morris PS. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Cochrane Database Syst Rev 2013; 7: CD004074. Rabe H, Diaz-Rossello JL, Duley L, Dowswell T. Effect of timing of umbilical cord clamping and other strategies to influence placental transfusion at preterm birth on maternal and infant outcomes. Cochrane Database Syst Rev 2012; 8: CD003248.
5
7 8
9
10 11
Bolisetty S, Dhawan A, Abdel-Latif M, Bajuk B, Stack J, Lui K; New South Wales and Australian Capital Territory Neonatal Intensive Care Units’ Data Collection. Intraventricular hemorrhage and neurodevelopmental outcomes in extreme preterm infants. Pediatrics 2014; 133: 55–62. Raju TN. Timing of umbilical cord clamping after birth for optimizing placental transfusion. Curr Opin Pediatr 2013; 25: 180–87. McAdams RM. Time to implement delayed cord clamping. Obstet Gynecol 2014; 123: 549–52. Hutchon DJ. Why do obstetricians and midwives still rush to clamp the cord? BMJ 2010; 341: c5447. Farrar D, Tufnell D, Airey R, Duley L. Care during the third stage of labour: a postal survey of UK midwives and obstetricians. BMC Pregnancy Childbirth 2010; 10: 23. Vain NE, Satragno DS, Gorenstein AN, et al. Effect of gravity on volume of placental transfusion: a multicentre, randomised, non-inferiority trial. Lancet 2014; published online April 17. http://dx.doi.org/10.1016/S01406736(14)60197-5. Gunther M. The transfer of blood between baby and placenta in the minutes after birth. Lancet 1957; 269: 1277–80. Bhatt S, Alison BJ, Wallace EM, et al. Delayed cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs. J Physiol 2013; 591: 2113–26.
www.thelancet.com Published online April 17, 2014 http://dx.doi.org/10.1016/S0140-6736(14)60411-6
In 2012, WHO updated its 2006 report on basic neonatal resuscitation and recommended delayed umbilical cord clamping for 1 to 3 min after birth, with the infant held at or below the level of the placenta.1 40 years of accumulated evidence supports this strategy, which increases iron stores and reduces the risk of iron deficiency anaemia in infants, a major global health benefit.2 For preterm infants, the practice reduces the rates of intraventricular haemorrhage by up to 50%.3 Because even mild intraventricular haemorrhage increases the risk for neurocognitive deficits, cerebral palsy, and developmental delay,4 the effect of delayed cord clamping for all infants could be huge. Therefore, many professional societies worldwide have issued similar guidelines, albeit with minor variations.5,6 But introduction of delayed cord clamping into practice has been sporadic,7,8 with logistical issues being one possible reason. Intuitively, to keep the newborn baby’s position below the level of the placenta in situ should maximise the volume of placental transfusion. However, trying to hold on to a wet, vigorously crying, and wriggling infant at the perineum for 2 min, in gloved hands, is awkward and can be risky. When the mother is waiting anxiously to hold her baby and the father is taking photographs, 2 min could seem like an eternity. The study by Nestor Vain and colleagues9 in The Lancet should bring a sigh of relief from those trying to incorporate delayed umbilical cord clamping into practice. The investigators randomly assigned 197 healthy term newborn babies to be held at vaginal level for 2 min after birth, and 194 infants to be placed on the maternal chest or abdomen for 2 min, after which the umbilical cord was clamped. With an elegant, time-tested method,10 investigators assessed placental transfusion by weighing the newborn baby soon after birth and again at 2 min, just after cord clamping. The results are convincing and show that gravity did not have an effect on volume of placental transfusion. The increase in mean weight was nearly identical between the groups; for newborn babies held at the level of the vaginal introitus, the mean weight gain was 56 g (SD 47; 95% CI 50–63), and, for those placed on their mother’s chest or abdomen, was 53 g (45; 46–59); difference 3 g (95% CI –5·8 to 12). Because 1 mL of blood weighs 1·05 grams, the estimated average volume
of placental transfusion was 50–53 mL, or about 14–15 mL/kg for an infant who weighs 3·5 kg at birth. The importance of this study should be viewed in the context of the long and convoluted history of the debate on cord clamping.2,3,5 Despite strong evidence for its benefits, and even after many systematic and scholarly reviews, editorials, and letters to editors, compliance in use of delayed cord clamping is poor; a postal survey in the UK found that for term births 74% of obstetricians and 41% of midwives clamp the cord within 20 s, and for preterm births the frequencies were 57% and 55%, respectively.8 So, where is the rub? Hutchon7 writes that instead of rushing to implement this practice, too often obstetricians and midwives rush to cut the cord, perhaps because they are unaware of the present evidence, or because of pragmatism and conflicting guidelines. Many do not realise that immediate cord clamping is an intervention, probably incorporated without proven benefits, into protocols on active management of the third stage of labour. Might there also be some reluctance because of the competing commercial interest in collection of cord blood for banking? The study by Vain and coworkers9 does not resolve all issues associated with this practice. The researchers recruited only vaginally-delivered healthy term infants— not caesarean births or preterm infants—and they excluded those requiring resuscitation. More research should be done to address these issues. Moreover, Vain and colleagues found a large variation between centres in weight gain at 2 min of age. They ascribe this finding to possible variations in the use of epidural anaesthetics that might change uterine activity, the timing of oxytocin administration in relation to birth, and to differences in the time of first weight measurements in relation to post-partum uterine contractions. As the practice becomes more widespread, new issues might emerge about the logistics of delayed cord clamping in modern obstetric practice. Some of these could include resuscitation with an unclamped umbilical cord, the optimum interval between delivery and cord clamping (does this vary by gestational age?), maternal or fetal haemorrhage, multifetal gestations, and fetal polycythaemia. Nevertheless, all questions might not have to be answered before pragmatic protocols are
www.thelancet.com Published online April 17, 2014 http://dx.doi.org/10.1016/S0140-6736(14)60411-6
Science Photo Library
Delayed cord clamping: does gravity matter?
Published Online April 17, 2014 http://dx.doi.org/10.1016/ S0140-6736(14)60411-6 See Online/Articles http://dx.doi.org/10.1016/ S0140-6736(14)60197-5
1
Comment
developed to incorporate this physiologically sound11 and immensely beneficial procedure into obstetric practice, and offer it to most, if not all, newborn infants.
4
Tonse N K Raju
6
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA [email protected] I declare that I have no competing interests. The opinions expressed here are those of the author and do not necessarily reflect those of the US National Institutes of Health or Department of Health and Human Services. 1 2
3
2
WHO. Guidelines on basic newborn resuscitation. 2012. Geneva, Switzerland: World Health Organization, 2012. McDonald SJ, Middleton P, Dowswell T, Morris PS. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Cochrane Database Syst Rev 2013; 7: CD004074. Rabe H, Diaz-Rossello JL, Duley L, Dowswell T. Effect of timing of umbilical cord clamping and other strategies to influence placental transfusion at preterm birth on maternal and infant outcomes. Cochrane Database Syst Rev 2012; 8: CD003248.
5
7 8
9
10 11
Bolisetty S, Dhawan A, Abdel-Latif M, Bajuk B, Stack J, Lui K; New South Wales and Australian Capital Territory Neonatal Intensive Care Units’ Data Collection. Intraventricular hemorrhage and neurodevelopmental outcomes in extreme preterm infants. Pediatrics 2014; 133: 55–62. Raju TN. Timing of umbilical cord clamping after birth for optimizing placental transfusion. Curr Opin Pediatr 2013; 25: 180–87. McAdams RM. Time to implement delayed cord clamping. Obstet Gynecol 2014; 123: 549–52. Hutchon DJ. Why do obstetricians and midwives still rush to clamp the cord? BMJ 2010; 341: c5447. Farrar D, Tufnell D, Airey R, Duley L. Care during the third stage of labour: a postal survey of UK midwives and obstetricians. BMC Pregnancy Childbirth 2010; 10: 23. Vain NE, Satragno DS, Gorenstein AN, et al. Effect of gravity on volume of placental transfusion: a multicentre, randomised, non-inferiority trial. Lancet 2014; published online April 17. http://dx.doi.org/10.1016/S01406736(14)60197-5. Gunther M. The transfer of blood between baby and placenta in the minutes after birth. Lancet 1957; 269: 1277–80. Bhatt S, Alison BJ, Wallace EM, et al. Delayed cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs. J Physiol 2013; 591: 2113–26.
www.thelancet.com Published online April 17, 2014 http://dx.doi.org/10.1016/S0140-6736(14)60411-6
