Chorioamnionitis, mechanical ventilation, and postnatal sepsis as modulators of chronic lung disease in preterm infants.

This case-control study of chronic lung disease (CLD) evaluated the hypothesis that chorioamnionitis promotes CLD and interacts with other risk factors for CLD, including mechanical ventilation and postnatal infection. We identified a population of 193 infants who met our case criteria for CLD whose birth weights were <or=1500 g. These infants were matched 1:1 with control infants for gestational age and hospital of birth. Univariable analyses revealed decreased CLD risk associated with histologic chorioamnionitis and increased risk associated with mechanical ventilation >7 days and culture-documented sepsis. In multivariable analyses, infants were at greatest risk for CLD when they had exposure to both chorioamnionitis and either mechanical ventilation >7 days (odds ratio, 3.2; 95% confidence interval, 0.9-11) or postnatal infection (odds ratio, 2.9; 95% confidence interval, 1.1-7.4). We conclude that prolonged mechanical ventilation or postnatal infection increases the risk of CLD among surviving preterm infants and that these 2 factors interact with antenatal infection to further increase the risk of CLD.