Relation between inspiratory oxygen fraction (FIO2) at 36 weeks of gestational corrected age (GCA) and forced expiratory volume in 1 s (zFEV1) or zFEV1/forced vital capacity (FVC) at adulthood. Airflow limitation (zFEV1) and airway obstruction (zFEV1/FVC) in 29 NCLD adult subjects in relation to the FIO2 at 36 weeks after conception measured while treated with oxygen administered to the spontaneously breathing infant, either in an incubator or in an oxygen tent. Regression analysis for zFEV1 revealed B=−6.4, with p=0.053, and B=−3,2, with p=0.29 for zFEV1/FVC.