Early growth characteristics and the risk of reduced lung function and asthma: A meta-analysis of 25,000 children

Abstract

Background Children born preterm or with a small size for gestational age are at increased risk for childhood asthma. Objective We sought to assess the hypothesis that these associations are explained by reduced airway patency. Methods We used individual participant data of 24,938 children from 24 birth cohorts to examine and meta-analyze the associations of gestational age, size for gestational age, and infant weight gain with childhood lung function and asthma (age range, 3.9-19.1 years). Second, we explored whether these lung function outcomes mediated the associations of early growth characteristics with childhood asthma. Results Children born with a younger gestational age had a lower FEV1, FEV1/forced vital capacity (FVC) ratio, and forced expiratory volume after exhaling 75% of vital capacity (FEF75), whereas those born with a smaller size for gestational age at birth had a lower FEV1 but higher FEV1/FVC ratio (P