Introduction: Structural lung abnormalities (SLA) are common in children born very preterm (<32 weeks? gestation). However there are no longitudinal imaging studies to assess progression or resolution of SLA over time in this group. We report SLA in childhood and young-adulthood, as well as neonatal risk factors for progression of SLA over time. 

Methods: Very preterm children (n=133; 10.9±0.6yrs, FEV₁ z-score -0.72±1.13; BPD n=83) and young adults (n=125; 19.4-years ±1.3; FEV₁ z-score -0.87±1.16; BPD n=79) born 1993-2003 underwent chest CT-scans. CT scans were scored using the modified Aukland Score. Mixed effects Poisson regression models were used to determine the change in CT outcomes with increasing age. Neonatal factors were included to determine if these risk factors influenced the change in CT score between visits.

Results: There was an overall decrease in total CT score for every one-year increase in age (IR 0.97, 95% CI 0.96, 0.98, p<0.001). Several NICU risk factors reduced the rate of improvement, including BPD status (IR 1.61, 95% CI 1.24, 2.10, p<0.001), septicaemia (IR 1.49, 95% CI 1.12, 1.98, p=0.006), postnatal steroids (IR 1.54, 95% CI 1.17, 2.01, p=0.002), duration of supplemental oxygen (IR 1.01, 95% CI 1.00, 1.01, p<0.001) and duration of mechanical ventilation (IR 1.01, 95% CI 1.01, 1.02, p<0.001). Hypoatennuation on expiration was the only score sub-component to worsen over the study period (IR 1.07, 95% CI 1.04, 1.09, p<0.001).

Conclusion: We observed an improvement in total chest CT scores between 11 and 19-years, which was attenuated in participants with a more severe neonatal history.