Published Online: February 13, 2014
Previous studies suggest that low birth weight is associated with an increased risk of asthma in childhood, but the results are conflicting, perhaps because of the different study populations. Also, the effect of preterm birth and infant catch-up growth on the association of low birth weight with asthma is not known, though recent studies suggest catch-up growth is associated with lower lung function, and increased risk of asthma. The lungs of preterm children have not yet fully developed, which makes them vulnerable and prone to respiratory morbidity.
In a study recently published in The Journal of Allergy and Clinical Immunology (JACI), Sonnenschein-van der Voort and colleagues conducted a meta-analysis of 147,252 children up to the age of 10, participating in 31 European cohort studies. The European population-based birth and mother-child cohorts exchanged original data of children born between 1989 and 2011, of whom information was available on gestational age or weight at birth, and preschool wheezing or school-age asthma.
The authors observed associations between birth weight and asthma outcomes that were largely explained by gestational age. Preterm birth (<37 weeks) was associated with an almost 1.5 fold increased risk of asthma, independent of birth weight. Additionally, not only preterm birth, but the full range of gestational age at birth was strongly associated with increased risks of asthma outcomes. The highest risk was observed in children born preterm with a high weight gain in the first year of life. The authors’ findings from this large scale meta-analysis suggests that rather than low birth weight, a shorter gestational age at birth and a higher weight gain in infancy are important risk factors for chronic obstructive lung disease such as asthma in later life.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.