Forced Oscillometry in Infants With Bronchopulmonary Dysplasia

Inclusion Criteria: Preterm Cohort: * Premature infants with BPD who are in room air based on the (per NICHD definition) * Premature infants with BPD who are receiving low flow O2 support and able to maintain normal spO2 in Room air for brief period ( up to 3 minutes) Term Cohort without pulmonary disease * Infants \>36 weeks gestational age without pulmonary disease * Infants \< 4 weeks of age Outpatient Cohort: * Former preterm infants \< 32 weeks at birth * Those with BPD based on NIH 2001 definition * Seen prior to 2 years of age Exclusion Criteria: * Infants with BPD requiring invasive or non-invasive positive pressure ventilation * Infants with BPD who have associated genetic diagnosis or major congenital anomalies.