Chorioamnionitis is strongly linked to preterm birth and to neonatal infection. The association between histological and clinical chorioamnionitis and cognitive, behavioral and neurodevelopmental outcomes among extremely preterm neonates is less clear. We evaluated the impact of chorioamnionitis on 18-22 month neurodevelopmental outcomes in a contemporary cohort of extremely preterm neonates.
To compare the neonatal and neurodevelopmental outcomes of three groups of extremely-low-gestational-age infants with increasing exposure to perinatal inflammation: no chorioamnionitis, histological chorioamnionitis alone, or histological plus clinical chorioamnionitis.
Longitudinal observational study.
Sixteen centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network.
2390 extremely preterm infants born <27 weeks' gestational age between January 1, 2006 and December 31, 2008 with placental histopathology and 18-22 months' corrected age follow-up data were eligible.
Main Outcome Measures
Outcomes included cerebral palsy, gross motor functional limitation, behavioral scores (according to the Brief Infant-Toddler Social and Emotional Assessment), cognitive and language scores (according to the Bayley Scales of Infant Development, 3rd-Edition) and composite measures of death/neurodevelopmental impairment. Multivariable logistic and linear regression models were developed to assess the association between chorioamnionitis and outcomes while controlling for important variables known at birth.
Neonates exposed to chorioamnionitis had a lower gestational age (GA) and had higher rates of early-onset sepsis and severe periventricular-intraventricular hemorrhage as compared with unexposed neonates. In multivariable models evaluating death and neurodevelopmental outcomes, inclusion of gestational age in the model diminished the association between chorioamnionitis and adverse outcomes. Still, histological+clinical chorioamnionitis was associated with increased risk of cognitive impairment as compared with no chorioamnionitis (Adjusted OR 2.4, [1.3- 4.3] without GA; Adjusted OR 2.0, [1.1-3.6] with GA as a covariate). Histological chorioamnionitis alone was associated with lower odds of death/neurodevelopmental impairment as compared with histological+clinical chorioamnionitis (Adjusted OR 0.68, [0.52-0.89] without GA; 0.66, [0.49-0.89] with GA). Risk of behavioral problems did not differ statistically between groups.
Conclusions and Relevance
Antenatal exposure to chorioamnionitis is associated with altered odds of cognitive impairment and death/neurodevelopmental impairment in extremely preterm infants.