Prenatal inflammation is associated with adverse neonatal outcomes.

Objective: The purpose of this study was to determine whether prenatal inflammation (as assessed by clinical chorioamnionitis, maternal temperature >38°C, or histologic chorioamnionitis) is associated with a composite adverse neonatal outcome.

Study Design: We performed a prospective cohort study of women at 22 weeks to 33 weeks 6 days' gestation with symptoms of labor (April 2009 to March 2012). Relevant maternal and neonatal exposures and outcomes were recorded. Multivariable logistic regression was performed to determine the association between prenatal inflammation and neonatal outcomes that were controlled for potential confounders.

Results: We analyzed 871 mother-infant pairs. The preterm birth rate was 42.0%. When we controlled for infant sex and modified the data by gestational age at delivery, prenatal inflammation remains a significant risk factor for adverse neonatal outcomes, despite advancing gestational age: clinical chorioamnionitis at 32 weeks' gestation (odds ratio [OR], 3.12; 95% confidence interval [CI], 1.02-9.52], at 36 weeks' gestation (OR, 8.88; 95% CI, 4.32-18.25), and at 40 weeks' gestation (OR, 25.30; 95% CI, 9.25-69.19); maternal temperature >38°C at 32 weeks' gestation (OR, 3.18; 95% CI, 0.66-15.42), at 36 weeks gestation (OR, 8.40; 95% CI, 3.60-19.61), and at 40 weeks gestation (OR, 22.19; 95% CI, 8.15-60.44); histologic chorioamnionitis at 32 weeks gestation (OR, 1.25; 95% CI, 0.64-2.46), at 36 weeks gestation (OR, 2.56; 95% CI, 1.54-4.23), and at 40 weeks gestation (OR, 5.23; 95% CI, 1.95-13.99).

Conclusion: The protective association with advancing gestational age is diminished when prenatal inflammation is present.