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Arch Dis Child 89:956-960 doi:10.1136/adc.2003.045971
  • Acute paediatrics

Neonatal respiratory morbidity at term and the risk of childhood asthma

  1. R Dobbie5
  1. 1Department of Obstetrics and Gynaecology, Cambridge University, Cambridge, UK
  2. 2Medical Research Council Biostatistics Unit, Institute of Public Health, Cambridge, UK
  3. 3Department of Public Health, Greater Glasgow NHS Board, Glasgow, UK
  4. 4Department of Fetal Medicine, The Queen Mother’s Hospital, Glasgow, G3 8SH, UK
  5. 5Information and Statistics Division, Common Services Agency, Edinburgh, UK
  1. Correspondence to:
    Professor G C S Smith
    Department of Obstetrics and Gynaecology, Cambridge University, Box 223, The Rosie Hospital, Robinson Way, Cambridge, CB2 2QQ, UK; gcss2{at}cam.ac.uk
  • Received 26 February 2004
  • Accepted 9 March 2004

Abstract

Objective: To determine whether neonatal respiratory morbidity at term is associated with an increased risk of later asthma and whether this may explain previously described associations between caesarean delivery and asthma.

Design: Retrospective cohort study using Scottish Morbidity Record (SMR) data of maternity (SMR02), neonatal (SMR11), and acute hospital (SMR01) discharges.

Setting: Scotland.

Participants: All singleton births at term between 1992–1995 in 23 Scottish maternity hospitals.

Main outcome measures: Hospital admission with a diagnosis of asthma in the principal position between 1992 and 2000.

Results: Children who had a diagnosis of transient tachypnoea of the newborn or respiratory distress syndrome were at increased risk of being admitted to hospital with a diagnosis of asthma (hazard ratio (HR) 1.7, 95% confidence interval (95% CI) 1.4 to 2.2, p<0.001). This association was observed both among children delivered vaginally (HR 1.5, 95% CI 1.1 to 2.0, p = 0.007) and among those delivered by caesarean section (HR 2.2, 95% CI 1.6 to 3.0, p<0.001). In the absence of neonatal respiratory morbidity, delivery by caesarean section was weakly associated with the risk of asthma in childhood (HR 1.1, 95% CI 1.0 to 1.2, p = 0.004). The strengths of the associations were similar whether the caesarean delivery was planned or emergency and were not significantly altered by adjustment for maternal, obstetric, and other neonatal characteristics.

Conclusions: Neonatal respiratory morbidity at term is associated with an increased risk of asthma in childhood which may explain previously described associations between caesarean delivery and later asthma.