Pathogenesis and prevention of chronic lung disease in the neonate.

Often used interchangeably, chronic lung disease (CLD) or bronchopulmonary dysplasia (BPD) develops primarily in extremely low birth weight infants weighing <1000 g who receive prolonged oxygen therapy and or positive pressure ventilation. CLD, which occurs in as many as 30 percent of infants born weighing <1000 g, contributes significantly to the morbidity and mortality seen in very low birth weight infants. Despite extensive research aimed at identifying risk factors and devising preventative therapies, many questions about the etiology and pathogenesis of BPD remain. This article reviews the embryologic development of the lung and the pathogenesis of CLD or BPD. The authors discuss some of the measures that have been used in an attempt to both prevent and treat BPD.