Northway et al reported clinical, radiographic, and histologic changes in the lungs of preterm infants who had respiratory distress syndrome (RDS) and were treated with oxygen and mechanical ventilation.[3]
Northway et al's original definition has been extensively modified over the last 4 decades. Bancalari et al’s definition involves ventilation criteria, an oxygen requirement at 28 days to maintain arterial oxygen tensions of more than 50 mm Hg, and abnormal findings on chest radiography.[4] Shennan et al proposed that an additional need for supplemental oxygenation at 36 weeks' postmenstrual age may be the most accurate indicator of pulmonary outcome;[5] this criterion decreased the large number of relatively healthy preterm infants Bancalari and others included in their definitions.