Chorioamnionitis: important risk factor or innocent bystander for neonatal outcome?

Chorioamnionitis as a major risk factor for spontaneous preterm birth, especially at earlier gestational ages, contributes to prematurity-associated mortality and morbidity. A gestation-independent effect of chorioamnionitis on neonatal outcome is much more difficult to assess. The influence of chorioamnionitis on neonatal outcome has become less evident with advances in neonatal care. A short-term beneficial effect of histological, but not clinical chorioamnionitis on incidence and severity of respiratory distress syndrome in preterm infants is evident. This maturational effect is accompanied by a susceptibility of the lung for further postnatal injury, which predisposes for bronchopulmonary dysplasia. Chorioamnionitis is associated with cystic periventricular leukomalacia, intraventricular hemorrhage and cerebral palsy in preterm infants, but its association with noncystic white matter disease is not clear yet. Prenatal inflammation/infection has been shown a risk factor for neonatal sepsis. A single course of antenatal steroids can be regarded safe in clinical as well as histological chorioamnionitis.