Structural and Functional Changes in the Preterm Lung

Abstract

Preterm infants, particularly those with bronchopulmonary dysplasia (BPD), experience long-term structural and functional pulmonary changes. BPD is a chronic lung disease of premature infants that results from a developmental arrest of the immature lung caused by multiple injurious factors such as mechanical ventilation, oxygen exposure, and prenatal or postnatal infections. Over the last 40 years, the survival of preterm infants with BPD has significantly increased due to the improvements in neonatal intensive care and in respiratory support. Many of the early BPD survivors are now well into their adulthood, and this is providing new information on the long-term respiratory outcomes, both structural and functional, in these former preterm infants. Increasing evidence from clinical and research data indicate that survivors of preterm birth and particularly those with BPD have prolonged abnormalities in their lung structure, imaging studies, and lung function. This population is at a greater risk for rehospitalizations due to respiratory illnesses, often being admitted into pediatric intensive care units. It is also likely that BPD survivors may have a reduced ability to reach their peak lung function at young adulthood and may have an accelerated decline in function with aging. Increasing evidence suggests that even infants without BPD and late-preterm infants are at increased risk for acute and chronic respiratory morbidities. This chapter provides a brief overview of normal lung developmental processes, BPD pathogenesis, and long-term respiratory outcomes, including structural and functional changes, in preterm survivors.