• Lung Physiology
• Paediatric Lung Disaese

Since bronchopulmonary dysplasia (BPD) was first described in 1967, the respiratory phenotype of the preterm infant has evolved.1 Over the past several decades, the management approach to treating these immature lungs, often in the saccular phase of development, has advanced leading to the survival of preterm infants born as early as 23–24 weeks gestational age. In the postsurfactant era, our understanding of the physiologic and structural pathogenesis of the respiratory system of these very low gestational age infants is poorly understood.

In this issue of Thorax, two Australian research teams delineate phenotypic features of the respiratory system in school age children and adolescents born prematurely. Simpson et al 2 present a case-control study evaluating a broad spectrum of lung function and imaging measures in former preterm (≤32 weeks gestation) school age (9–11-year-old) children born between 1997 and 2003. Doyle et al 3 present a prospective cohort study of lung function measures at school age (8 years) and again in late adolescence (18 years) in former premature children (≤28 weeks gestation and/or <1000 g birth weight) born between 1991 and 1992. Both preterm populations consisted of children with and without the diagnosis of BPD.

Prior investigators detail lung function impairment in school age, adolescent and adult individuals born prematurely.4 ,5 Unlike the two reports in this issue of Thorax, few prior studies evaluated participants born in the so-called postsurfactant or ‘new BPD’ era. Other confounding variables in prior studies include inconsistent definitions and application of the BPD diagnosis, as well as lack of uniform lung function reference values that span across all ages.6 Both Australian groups defined BPD based on …