Background: Cheap and effective interventions are needed to reduce the risk of infant anaemia in developing countries. Delayed cord clamping (DCC) has been shown to be a simple, safe and cost-free delivery procedure that augments red cell mass in appropriate-for-gestational-age term and preterm infants. It is not known, however, whether DCC is similarly safe and effective in small-for-gestational-age (SGA) infants. We analysed the available evidence to generate a balanced inference on the use of DCC in developing countries.
Objectives: To examine the short- and long-term effects in SGA infants of DCC compared with immediate clamping, and to assess the relationship between time of clamping and the potential postnatal haematological complications of DCC in SGA infants.
Search strategy: PubMed (1966 to January 2006), EMBASE (1988 to January 2006) and The Cochrane Library (Issue 1, 2006) were searched. Reference lists of published trials were examined and major journals of perinatal and tropical medicine were hand-searched.
Selection criteria: Randomised and quasi-randomised trials comparing delayed with immediate cord clamping in infants born between 30 and 42 completed weeks of gestation and which included a proportion of SGA infants.
Data collection and analysis: Three reviewers assessed eligibility and trial quality.
Main results: To date, no trials have specifically reported the effects of DCC in SGA infants. Three trials were included, of 190 term and 40 preterm infants, a proportion of whom were SGA. DCC was associated with higher haemoglobin levels in term infants at follow-up [two trials, 127 infants, weighted mean difference (WMD) 9.17 g/L, 95% confidence interval (CI) 5.94-12.40]. In preterm infants, the proportion who required a blood transfusion in the 1st 6 weeks after birth was lower after DCC (one trial, 38 infants, RR 0.56, 95% CI 0.34-0.94). It was not possible to infer from the available data whether SGA infants were at greater risk of adverse effects in the early neonatal period.
Conclusions: DCC in a group that contains both AGA and SGA infants was associated with higher haemoglobin levels at 2-3 months of age in term infants and a reduction in the number of blood transfusions needed in the 1st 4- 6 weeks of life in preterm infants. No reliable conclusions could be drawn about the potential adverse effects of DCC. The paucity of information on DCC in SGA infants justifies further research, especially in developing countries where the baseline risk for polycythaemia-hyperviscosity syndrome is likely to be lower than in industrialised countries.