[2] It is also more common in infants with low birth weight (LBW) and those who receive prolonged mechanical ventilation to treat respiratory distress syndrome.

The definition of bronchopulmonary dysplasia has continued to evolve primarily due to changes in the population, such as more survivors at earlier gestational ages, and improved neonatal management including surfactant, antenatal glucocorticoid therapy, and less aggressive mechanical ventilation.

[7] Physical findings:[citation needed] Prolonged high oxygen delivery in premature infants causes necrotizing bronchiolitis and alveolar septal injury, with inflammation and scarring.

Today, with the advent of surfactant therapy and high frequency ventilation and oxygen supplementation, infants with BPD experience much milder injury without necrotizing bronchiolitis or alveolar septal fibrosis.

[10][11] The classic diagnosis of bronchopulmonary dysplasia may be assigned at 28 days of life if the following criteria are met:[citation needed] The 2006 National Institute of Health (US) criteria for BPD (for neonates treated with more than 21% oxygen for at least 28 days)[12] is as follows:,[13][14] Infants with bronchopulmonary dysplasia are often treated with diuretics that decrease fluid in the alveoli where gas exchange occurs and bronchodilators that relax the airway muscles to facilitate breathing.

[15] To alleviate bronchopulmonary dysplasia, caffeine is another commonly used treatment that reduces inflammation and increases lung volume thereby improving extubation success and decreasing the duration of mechanical ventilation.

[18] For babies seven days old and older, "late systemic postnatal corticosteroid treatment" may reduce the risk of death and of bronchopulmonary dysplasia.