568: Association of chorioamnionitis and its duration with neonatal morbidity and mortality

Abstract

Chorioamnionitis, or intraamniotic infection, may complicate >50% of preterm births and is frequently diagnosed among term women in labor. There is a lack of recent, population-level data from both preterm and term infants to quantify the impact of chorioamnionitis on neonatal outcomes. We investigated the association of chorioamnionitis, and secondarily its duration, on neonatal morbidity and mortality for infants born <34 weeks versus ≥34 weeks gestation. A multi-site, nationally representative, observational study of singleton deliveries from the U.S. Consortium on Safe Labor Study. The primary exposure was chorioamnionitis, and secondarily, the duration of chorioamnionitis measured by the duration of intrapartum antibiotic therapy. The primary composite neonatal outcome included: pneumonia, seizure, necrotizing enterocolitis, sepsis, periventricular, intraventricular or cerebral hemorrhage, mechanical ventilation, and neonatal death. Logistic regression with generalized estimating equations was used, adjusting for maternal age, parity, race, pre-gestational diabetes, chronic hypertension, mode of delivery, year of delivery, and infant gender. Among 221,274 deliveries, 9,633 (4.4%) were <34 weeks. Chorioamnionitis was 4-times more frequent <34 weeks compared to ≥34 weeks (8.6% vs. 1.9%; p<0.001). The adjusted odds of the composite neonatal adverse outcome <34 weeks was approximately 2-fold higher among infants exposed to chorioamnionitis versus those who were not (62.0% vs. 47.7%; adjusted odds ratio, AOR: 1.93; 95% CI: 1.32 – 2.84), and was approximately 3.5-fold higher for infants born ≥34 weeks (9.2% vs. 2.5%; AOR: 3.44; 95% CI: 2.45 – 4.81) (Table). The odds ratios for adverse neonatal outcomes were stable across the estimated duration of chorioamnionitis for infants born both <34 weeks and ≥34 weeks. In a large nationally representative sample of US births, chorioamnionitis was associated with an approximately 2- and 3.5-fold increased odds of neonatal morbidity and mortality <34 and ≥34 weeks, respectively, regardless of its estimated duration. These data provide a further evidence base to guide obstetric and pediatric providers in the timely management of a common infectious condition to improve neonatal health.