Objective: To determine the effects of chorioamnionitis and antenatal corticosteroids on matrix metalloproteinase-8 (MMP-8) concentrations in bronchoalveolar lavage (BAL) fluid from preterm babies in the first week of life.
Design: Prospective observational study.
Setting: Regional neonatal intensive care unit.
Patients: Thirty five ventilated preterm babies < 33 weeks gestation, seven of whom were born after chorioamnionitis, which was diagnosed histologically as the presence of inflammatory cells in the chorioamnionic plate.
Methods: MMP-8 was measured by enzyme linked immunosorbent assay (ELISA) in 90 serial BAL samples taken during the first six postnatal days. The median MMP-8 concentration for each baby was calculated.
Results: Median MMP-8 concentrations were higher in the chorioamnionitis group than in those without (43 v 5 ng/ml). Partial or complete courses of antenatal corticosteroids had no effect on MMP-8 concentrations.
Conclusions: Higher concentrations of MMP-8 are found in BAL fluid from preterm babies from pregnancies complicated by chorioamnionitis. This type I collagenase may contribute to the lung injury that occurs in some babies with respiratory distress syndrome.