Epidemiology of preterm birth
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《英国医生杂志》
EDITOR—In noting antenatal steroids and exogenous surfactants as two specific perinatal interventions that have contributed to trends in improved outcomes for very preterm infants, Hutchon thinks that we have omitted to include delayed cord clamping. We argue that whereas there is robust evidence from larger trials and systematic reviews for both prophylactic steroids and surfactants,1 2 there is currently continued uncertainty in the published evidence base about the effect of delayed cord clamping on mortality and disability outcomes.
The recently published Cochrane review of this intervention identifies seven trials in which a total of 297 infants participated.3 There is some evidence from meta-analysis of data from these trials that delayed cord clamping results in fewer infants receiving blood transfusions in the neonatal period, but there is little other evidence of benefit. Infants in the delayed clamping group had higher peak serum bilirubin concentration in the early neonatal period. There is insufficient evidence of effect on mortality, respiratory outcomes, the incidence of severe intraventricular haemorrhage or periventricular leucomalacia, or the incidence of necrotising enterocolitis.3 Most importantly, there are not yet any data on the effect of this intervention on neurodevelopmental outcomes in the longer term. Further large trials are needed to provide these data in order to clarify whether the practice of delayed cord clamping for very preterm infants should be adopted.
Janet Tucker, senior researcher
Dugald Baird Centre, Department of Obstetrics and Gynaecology, University of Aberdeen, Aberdeen AB25 2ZL j.s.tucker@abdn.ac.uk
William McGuire, senior lecturer in neonatal medicine
Tayside Institute of Child Health, University of Dundee, Dundee DD1 9SY
Competing interests: None declared.
References
Crowley P. Prophylactic corticosteroids for preterm birth. Cochrane Library. Issue 3. Chichester: John Wiley, 2004.
Soll RF, Blanco F. Natural surfactant extract versus synthetic surfactant for neonatal respiratory distress syndrome (Cochrane review). Cochrane Library. Issue 4. Chichester: John Wiley, 2004.
Rabe H, Reynolds G, Diaz-Rossello J. Early versus delayed umbilical cord clamping in preterm infants (Cochrane review). Cochrane Library. Issue 4. Chichester: John Wiley, 2004.
The recently published Cochrane review of this intervention identifies seven trials in which a total of 297 infants participated.3 There is some evidence from meta-analysis of data from these trials that delayed cord clamping results in fewer infants receiving blood transfusions in the neonatal period, but there is little other evidence of benefit. Infants in the delayed clamping group had higher peak serum bilirubin concentration in the early neonatal period. There is insufficient evidence of effect on mortality, respiratory outcomes, the incidence of severe intraventricular haemorrhage or periventricular leucomalacia, or the incidence of necrotising enterocolitis.3 Most importantly, there are not yet any data on the effect of this intervention on neurodevelopmental outcomes in the longer term. Further large trials are needed to provide these data in order to clarify whether the practice of delayed cord clamping for very preterm infants should be adopted.
Janet Tucker, senior researcher
Dugald Baird Centre, Department of Obstetrics and Gynaecology, University of Aberdeen, Aberdeen AB25 2ZL j.s.tucker@abdn.ac.uk
William McGuire, senior lecturer in neonatal medicine
Tayside Institute of Child Health, University of Dundee, Dundee DD1 9SY
Competing interests: None declared.
References
Crowley P. Prophylactic corticosteroids for preterm birth. Cochrane Library. Issue 3. Chichester: John Wiley, 2004.
Soll RF, Blanco F. Natural surfactant extract versus synthetic surfactant for neonatal respiratory distress syndrome (Cochrane review). Cochrane Library. Issue 4. Chichester: John Wiley, 2004.
Rabe H, Reynolds G, Diaz-Rossello J. Early versus delayed umbilical cord clamping in preterm infants (Cochrane review). Cochrane Library. Issue 4. Chichester: John Wiley, 2004.