Abstract
BackgroundThe association between birthweight and asthma, eczema and rhinoconjunctivitis is conflicting.
AimsTo examine the association between birthweight and symptoms of asthma, eczema and rhinoconjunctivitis.
MethodsParents or guardians of children aged 6-7yr completed written questionnaires about symptoms of asthma, rhinoconjunctivitis and eczema, and several risk factors, including birthweight.
ResultsThere were 162,324 children from 60 centres in 26 countries. Low birthweight (<2.5kg) was associated with an increased risk of symptoms of asthma (current wheeze odds ratio=1.20; 95% confidence interval=1.12-1.30). Low birthweight was associated with a lower risk of eczema ever. Low birthweight was not associated with rhinoconjunctivitis. Large babies (birthweight 4.5kg) were not associated with any of these outcomes.
ConclusionsThis study has confirmed that low birthweight is a risk factor for symptoms of asthma, but not for rhinoconjunctivitis. The findings for eczema are equivocal.