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.