Chorioamnionitis--the good or the evil for neonatal outcome?

Chorioamnionitis represents a major risk factor for preterm birth and contributes to prematurity-associated morbidity and mortality. Comparison of studies addressing neonatal outcome after exposure to either histological or clinical chorioamnionitis is hampered by the great heterogeneity regarding study cohorts and disease definitions which were applied. Moreover, the impact of exposure to inflammation in utero on neonatal outcome has become less evident with major advances in perinatal and neonatal care. Histologic chorioamnionitis evidently is associated with a reduction of incidence and severity of respiratory distress syndrome. Short-term maturational effects on the lungs of ventilated extremely premature infants are, however, accompanied by a greater susceptibility of the lung, eventually contributing to an increased risk of bronchopulmonary dysplasia. Chorioamnionitis has been shown associated with increased rate of early-onset sepsis but, according to recent data, histological chorioamnionitis might be protective against late-onset sepsis. Inconsistent data exist concerning the true role of chorioamnionitis in the development of brain lesions such as cystic periventricular leukomalacia, diffuse white matter disease, and intraventricular hemorrhage. However, an association with the development of cerebral palsy has been reported.