The relationship between fetal growth and the development of asthma and atopy in childhood

We analysed data from the Dunedin longitudinal study of children born in 1972-1973. There were 734 children (71 % of the living cohort) in whom the relevant information was available at 13 years (serum total IgE was measured at 11 years). Infants with a birth weight of less than 3.0 kg had an odds ratio for reported asthma of 0.3 (95% C.I 0.1-0.6) compared to those with a birth weight greater than 3.0 kg. Infants with a birth length of 56 cm or more had an odds ratio of 3.4 (95% C.I1.4-8.2) for reported asthma compared with those with a birth length of 50-55.9 cm. Infants with a birth head circumference of 37 cm or more had an odds ratio of 3.0 (95% C.I1.46.3) for having an elevated serum total IgE, compared with those with a birth head circumference of 34-36.9 cm. Infants with a head circumference at birth of less than 34 cm had an odds ratio for a positive skin prick test of 0.5 (95% C.I 0.3-0.8) compared to those with a head circumference of 34-36.9 cm. There was no association between reported eczema or hayfever and any of the birth parameters. This study strengthens the hypothesis that factors responsible for fetal growth may lead to programming of the developing respiratory or immune system.