Foetal and infant growth patterns, airway resistance and school-age asthma.

Background and objective Preterm birth, low birth weight and rapid infant weight gain are associated with increased risks of asthma symptoms in childhood. The underlying mechanism may include persistently higher airway resistance (Rint). The aim of our study was to examine the associations of longitudinally measured foetal and infant growth characteristics with Rint and asthma outcomes in school-age children. Methods This study was embedded in a population-based prospective cohort study in Rotterdam, The Netherlands. Foetal growth was estimated by ultrasound in the second and third trimesters. Infant growth was measured at birth, 3, 6 and 12 months. At age 6 years, Rint was measured, and information about wheezing and asthma was obtained by questionnaires. The number of subjects per analysis differed per available outcome (3954–5066 subjects). Results Longitudinal growth analyses showed that school-age children with increased Rint had lower foetal length growth and weight gain, and lower infant length growth. Children with persistent wheezing until age 6 years and physician-diagnosed asthma had a higher Rint compared with children who never wheezed or without asthma (difference z-scores Rint: 0.58 (0.19, 0.97) and 0.55 (0.15, 0.95), respectively). Conclusion Rint in school-age children is influenced by foetal growth restriction and is associated with asthma outcomes. See Editorial, page 574