Lung function outcomes in adults born extremely preterm across three decades of advancing perinatal medicine.

Aim: Advances in perinatal medicine from 1980 to 2000 improved survival in extremely preterm (EP) neonates. Long-term effects of these developments remain unclear, and we aimed to investigate potential cohort effects on adult lung function.

Methods: Three 18-year-old population-based cohorts born at ≤28 weeks gestation or with birthweight ≤1000 g during 1982-85, 1991-92 and 1999-2000 and term-controls underwent spirometry, body plethysmography, and tests of lung diffusing capacity, bronchodilator reversibility, and airway hyperresponsiveness. We used Welch's t-tests to compare term- with EP-born as a group and split by bronchopulmonary dysplasia (BPD), and regression models to test group/cohort interactions.

Results: In all EP-born cohorts, z-scores for FEV₁, FEV₁/FVC, FEF_25%-75%, DLCO and KCO were reduced compared with term-born. For the 82-85, 91-92 and 99-00 cohorts, deficits for z-FEV₁ and z-DLCO were 1.23 and 0.53; 0.68 and 0.92; and 0.51 and 0.57, respectively (p ≤0.01 for all). Cohort analyses showed stable lung function across the three cohorts overall, but improvements across cohorts for the BPD subgroups in z-FEV₁, z-FEV₁/FVC, and z-FEF_25%-75%.

Conclusion: Adults born EP across three formative decades of neonatal care had stable lung function overall, with notable improvements in BPD subgroups across cohorts.