The purpose of this study is to evaluate how easily gas can be taken up by the lung. We are comparing infants born premature <32 weeks gestation to infants born full term >37 weeks. We hope to evaluate the differences between the two groups in order to learn more about premature lung growth and development.

We hypothesize that infants who were born prematurely but are clinically without chronic respiratory disease have a lower lung diffusion capacity than healthy infants born at full term, when evaluated at comparable post-conception ages. In addition, prematurely born infants that develop chronic lung disease have an even lower diffusion capacity than healthy premature infants and full term infants. A lower diffusion capacity, when normalized to lung volume, would be consistent with decreased alveolarization and alveolar surface area in the infants born prematurely. We will study the age range of 1 to 24 month as this represents the period of rapid lung growth.

Inclusion Criteria:

• Group 1 Infants born at < 32 weeks gestation with Chronic lung disease
• Group 2 Infants born at <32 weeks gestation without Chronic lung disease
• Group 3 Infants born full term at >37 weeks

Exclusion Criteria:

• Group 1 and Group 2--No heart disease, no oxygen requirement
• Group 3--No hospitalization for respiratory illness, No asthma, No heart disease, No history of wheezing, asthma or treatment with asthma medications.

Recruitment for premature infants were through Infant Lung Disease clinic at Riley Hospital for Children and IU NICU. Healthy full term infants were recruited through advertisements in local newspapers.