The effect of chorioamnionitis on perinatal outcome in preterm gestation.

Six hundred ninety-eight patients with premature rupture of the membranes between 26 and 34 weeks were managed expectantly without the use of tocolytics or corticosteroids. Of these, 92 (13 per cent) developed chorioamnionitis. Although latency period (defined as the time from rupture of the membranes to the onset of labor) had no correlation with the incidence of chorioamnionitis, the mean latency period was significantly shorter for those gestations complicated by infection. The risk of chorioamnionitis was found to be inversely related to gestational age. The length of labor, once chorioamnionitis was diagnosed, had no correlation with neonatal outcome, but the development of chorioamnionitis led to a statistically significant increase in neonatal mortality, infection rate, incidence of respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH), and five-minute Apgar score less than 7. Maternal endometritis and other complications of infection were increased in the presence of chorioamnionitis, especially in patients delivered by Cesarean section. Useful predictors of early chorioamnionitis were maternal leukocytosis, fetal tachycardia, and elevated maternal C-reactive protein titers.