Which chronic lung disease commonly affects preterm infants after prolonged oxygen therapy?

• A. Bronchopulmonary dysplasia
• B. Respiratory distress syndrome
• C. Croup
• D. Epiglottitis

Answer: (A)

Prolonged oxygen therapy in very preterm infants can trigger a chronic lung injury called bronchopulmonary dysplasia, a persistent lung disease driven by inflammatory injury and disrupted lung development. In these infants, the immature airways and alveoli are damaged by oxygen exposure and often by mechanical ventilation, leading to arrested alveolar growth, fibrosis, and airway remodeling. This results in ongoing respiratory support needs and reduced gas exchange capacity beyond the neonatal period. The condition is typically considered when a preterm infant continues to require supplemental oxygen beyond the early newborn days—often defined by oxygen dependence at about 28 days of life or around 36 weeks postmenstrual age. This distinguishes it from respiratory distress syndrome, which is an acute surfactant-deficiency problem presenting soon after birth and usually improving with treatment. Croup and epiglottitis are acute upper-airway illnesses and do not represent a chronic lung condition caused by prolonged neonatal oxygen exposure.