Less iron deficiency anaemia after delayed cord-clamping

Umbilical cord-clamping and cutting, by far the most frequently performed intervention in humans, takes place in the third stage of labour, which is defined as the period from expulsion of the fetus to expulsion of the placenta. The best timing of cordclamping in term infants has long been debated, and, until recently, research has been equivocal. Early clamping is some time between 10 and 60 seconds after birth, while delayed clamping is between 2 minutes and cessation of cord pulsations. Late clamping is mainly seen in traditional African home deliveries, where the cord is cut after placental descent into the vagina. Immediately after the birth of a baby, placental blood continues to flow in the direction of the child. The total fetoplacental blood volume is about 120 ml/ kg of fetal weight, and the distribution of blood between fetus and placenta is roughly in a ratio of 2:1. This distribution remains unchanged if the cord is clamped early. Allowing placental transfusion to occur for at least 3 minutes results in greater infant blood volume (ratio 5:1). The rate of placental transfusion is influenced by the position of the delivered infant. From 10 cm above the level of the placenta (on the abdomen of the mother) to 10 cm below the level of the placenta (on the birthing bed), infants receive the maximum possible amount of blood for at least 3 minutes after birth. Keeping the infant 40 cm below the placenta hastens placental transfusion to near completion within 1 minute. Until the turn of the new millennium, early cordclamping was considered to be standard good care. Obstetricians believed that early clamping (next to the administration of oxytocics and controlled cord traction) was essential to reduce maternal blood loss in the third stage of labour. However, early clamping has been accepted in obstetrical practice without much consideration. A Cochrane review published in 2008 studied the effects of different cord-clamping times on maternal blood loss and found that delayed clamping poses no additional threat to women. The World Health Organization, the International Federation of Gynecology and Obstetrics and the International Confederation of Midwives have now removed the early clamping practice from their guidelines. Neonatologists and paediatricians frequently cautioned about polycythaemia, hyperviscosity syndrome and hyperbilirubinaemia as adverse effects of placental transfusion, and therefore also advocated early clamping. Meta-analyses in 2006 and 2007, however, independently showed that delayed clamping causes no danger to the newborn, and actually improves the haematological and iron status of the infant. A Mexican trial showed that the beneficial effect of delayed cord-clamping on infant iron status could be detected even 6 months after birth. Although scientific evidence had demonstrated that the benefits of delayed cord-clamping outweigh the risks to mother and child, as yet, implementation of delayed clamping has not been very successful. Changing the practice of cord-clamping poses unique challenges because, although paediatricians are responsible for the long-term wellbeing of newborns, the umbilical clamp is applied by midwives and obstetricians. This challenge may explain why there are no countries in which a policy of delayed cordclamping has been successfully implemented. The only paper reporting an approach to implementing change was from a hospital in Peru. After introduction of a national statement supporting delay of cord-clamping, a 3-day workshop was organised involving all midwives at the hospital. Following this, the mean cord-clamping time increased from 57 seconds before the educational intervention to 170 seconds thereafter. In this issue of Paediatrics and International Child Health the same group reports on progress in the practice of cord-clamping. On the basis of earlier published studies on the timing of cord-clamping, the authors suspected that maternal anaemia during pregnancy possibly modifies the beneficial effect of delayed cord-clamping on infant haemoglobin status. To test this hypothesis, they analyzed maternal haemoglobin levels before delivery, and infant haemoglobin levels at 4 and 8 months. Mother–infant Correspondence to: P van Rheenen, Faculty of Medical Sciences, University of Groningen – University Medical Center Groningen, 9700 RB Groningen, The Netherlands. Email: p.f.van.rheenen@umcg.nl