The Lancet 2006; 367:1956-1958
Delayed cord clamping increases infants' iron stores
Judith Mercer and Debra Erickson-Owens
It is startling to see how a seemingly insubstantial change in practice might affect long-term results for infants. When a medical text recommended immediate cord clamping in 1913, science was in its infancy and expert opinion guided practice. Today, we have the benefit of scientific evidence to advise our actions. The article in today's Lancet by Camila Chaparro and colleagues1 provides additional weight to the growing evidence that our haste to clamp the umbilical cord and pass the baby off is ill-advised. The mounting evidence that delayed cord clamping benefits both term and preterm infants continues to build.2,3
Chaparro and colleagues' international interdisciplinary study with 358 randomised infants shows that waiting 2 min before clamping the umbilical cord provided the infants with more body iron at 6 months of age without causing any harm at birth. The rationale for the study—the link between iron deficiency in infancy and neurodevelopmental delays—is well founded. The number of infants in the study was ambitious and the protocol for the 6-month follow-up was meticulously planned. The exclusion criteria were carefully selected to rule out women with conditions that negatively affect neonates. Most importantly, the team used multiple methods for identifying the main outcome variable of iron status at 6 months of age. There were no differences between the groups of infants on the concerns about harm: neonatal jaundice or polycythaemia. The protocol required that obstetricians and midwives wait up to 2 min to clamp and cut the umbilical cord. Studies in which cord clamping was delayed for 3 min or longer also failed to show harm with the assigned delay in cord clamping.2
Infants with delayed cord clamping in Dewey and colleagues' study were held level with the mother's body during the 2-min wait. Lowering the infant can speed the transfusion.4 In our randomised trial of a brief delay (30–45 s) in cord clamping at preterm births, we lowered the infant below the introitus or incision to hasten transfusion.5 However, if one places the infant on the mother's abdomen briefly before cutting the cord, the infant might receive less placental transfusion.6
The results of Chaparro and colleagues' study suggest that a modification might be indicated in the active management of the third-stage programme for developing countries, in which anaemia in infancy is often endemic. Active management of the third stage prevents maternal haemorrhage after birth. As defined initially and researched, the process involved three steps: (1) a drug is used to contract the uterus; (2) the cord is clamped immediately; and (3) traction is applied to the cord to speed delivery of the placenta. The most important part of active management is getting the uterus to contract to avoid uterine atony. There is a fear that giving the drug to contract the uterus (uterotonic) with the infant still attached to the umbilical cord would cause “overtransfusion.” Yao and co-workers showed that giving such a drug and delaying cord clamping did not result in overtransfusion because the blood volumes of the infants in this study never went above 90 mL/kg, even with a 5–6-min wait to clamp.7 Two of the large studies on active management of the third stage reported that infants who had immediate cord clamping weighed substantially less than the infants who had delayed cord clamping.8,9 We believe that more research on the use of uterotonic drugs while leaving the cord intact is essential.
Chaparro and colleagues' study increases concern about the ethics of routine cord-blood collection without adequate informed consent and the advertisement of cord blood as “medical waste.” It is very plausible that those magical stem cells found in cord blood have multiple protective and preventive roles to play in an infant's developing body.10 We support the American Academy of Pediatrics' statement which does not recommend cord-blood collection and storage unless there is a known family need.11 However, that valuable cord blood should not be medical waste—let the infants have what they need first.
This excellent study by Chaparro and colleagues, the largest ever done on delayed cord clamping with long-term follow-up, adds important evidence in favour of delayed cord clamping at the births of term infants.
We declare that we have no conflict of interest.
1. Chaparro CM, Neufeld LM, Tena Alavez G, Eguia-Liz Cedillo R, Dewey KG. Effect of timing of umbilical cord clamping on iron status in Mexican infants: a randomised controlled trial. Lancet 2006; 367: 1997-2004.
2. van Rheenen P, Brabin B. Late umbilical cord-clamping as an intervention for reducing iron deficiency anaemia in term infants in developing and industrialised countries: a systematic review. Ann Trop Paediatr 2004; 24: 3-16.
3. Rabe H, Reynolds G, Diaz-Rossello J. Early versus delayed umbilical cord clamping in preterm infants. Cochrane Database Syst Rev 2004; 4:CD003248.
4. Yao AC, Lind J. Effect of gravity on placental transfusion. Lancet 1969; 2: 505-508.
5. Mercer JS, Vohr BR, McGrath MM, Padbury JF, Wallach M, Oh W. Delayed cord clamping in very preterm infants reduces the incidence of intraventricular hemorrhage and late-onset sepsis: a randomized, controlled trial. Pediatrics 2006; 117: 1235-1242.
6. Grisaru D, Deutsch V, Pick M, et al. Placing the newborn on the maternal abdomen after delivery increases the volume and CD34 cell content in the umbilical cord blood collected: an old maneuver with new applications. Am J Obstet Gynecol 1999; 180: 1240-1243.
7. Yao AC, Hirvensalo M, Lind J. Placental transfusion-rate and uterine contraction. Lancet 1968; 1: 380-383.
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9. Prendiville WJ, Harding JE, Elbourne DR, Stirrat GM. The Bristol third stage trial: active versus physiological management of third stage of labour. BMJ 1988; 297: 1295-1300.
10. Ende N, Reddi AS. Administration of human umbilical cord blood to low birth weight infants may prevent the subsequent development of type 2 diabetes. Med Hypotheses 2006; 66: 1157-1160.
11. American Academy of Pediatrics. Cord blood banking for potential future transplantation: subject review. Pediatrics 1999; 104: 116-118i.