Respiratory function in adolescence in relation to low birth weight, preterm delivery, and intrauterine growth restriction

Objectives: To study the associations between respiratory function in 18-year-old male subjects and birth weight, preterm delivery, and intrauterine growth restriction (IUGR). Methods: Population-based birth cohort. Subsamples of 118 male subjects with low birth weight (LBW) [<2,500 g] and 236 male subjects with normal birth weight were examined at the age of 18 years. Results: In the crude analysis, subjects with LBW showed reductions in FEV₁ and FVC of 0.166 L and 0.141 L, respectively, compared to those born weighing ≥ 2,500 g. These differences were not significant after adjustment for confounding. When subjects with LBW were stratified into those with preterm delivery and those with IUGR, the latter presented a significant reduction in both FEV₁ and FVC, when compared to the reference group. These differences also disappeared after adjustment for confounders. Preterm delivery per se was also not associated with poor lung function. Conclusions: In this population, LBW was not associated with respiratory function in 18-year-old male subjects.