Development of lung function in children born preterm with and without bronchopulmonary dysplasia - a follow-up study at 12 years of age

Introduction: Pulmonary disease after very preterm birth may cause permanent lung damage and as a consequence, lung function impairment in long-term survivors, bronchopulmonary dysplasia being one of the earliest manifestation. Aims: The aim of this study was to assess lung function in children 12 years of age, born very preterm and compare with children born at term. In addition we determined the impact of BPD and prematurity during childhood. Methods: Spirometry, impulse oscillometry, body plethysmograhy and diffusing capacity was performed at 12 years of age in 98 children, born at gestational age of 22-31 weeks (median 27 weeks and birth weight 950g). Age-matched children born at term were included as controls (n=17). BPD was defined as need for supplemental oxygen at 36 weeks postmenstrual age. Results: Prematurity was associated with lower forced expiratory flow (FEF25-75), p=0.05, higher total (R5) and peripheral (R5-20) resistance, p=0.01 resp p<0.01, lower capacity for elastic recoil (X5, Fres and Ax), all p<0.01. Prematurity was also associated with lower diffusion capacity, p=0.01 and higher residual volume, p=0.02. Preterm children with BPD showed no significant lung function impairment at the age of 12 compared to preterm children without BPD. Conclusion: Preterm birth is associated with an increased risk of significant obstructive airway disease and lung function impairment at the age of 12, regardless of BPD diagnosis. Children born preterm would benefit from regular assessment of lung function to give an insight regarding long-term sequele and respiratory health throughout adolescence and adulthood.