Association of Histologic Chorioamnionitis with Perinatal Brain Injury and Early Childhood Neurodevelopmental Outcomes among Preterm Neonates

Acute chorioamnionitis refers to the neutrophilic inflammation of the placental tissues thought to result from an ascending bacterial infection. It is considered a major factor associated with pretermbirth and has been estimated to occur in 40%to 80% of preterm deliveries. Chorioamnionitis is associated with several adverse neonatal outcomes, including respiratory distress syndrome, sepsis, bronchopulmonary dysplasia, and death. Clinical studies examining brain injury and neurodevelopmental outcomes among infants with chorioamnionitis have yielded inconsistent results. Most of these studies have focused on intraventricular hemorrhage (IVH) and cystic periventricular leukomalacia. Because the incidence of cystic periventricular leukomalacia has greatly decreased during the past decades concurrent with improvements in neonatal intensive care, punctate white matter injury (WMI) is increasingly recognized as the most prevalent pattern of brain injury among preterm neonates. The researchers performed a prospective cohort study conducted across 3 academic centers in Canada, the Netherlands, and the United States. Children who were born preterm (24-32 weeks' gestation) and who had undergone a placental pathologic evaluation, magnetic resonance imaging (MRI) as soon as clinically stable, and Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley III) assessments between 18 and 24 months' corrected age (CA) were included. Magnetic resonance imaging scans were assessed for grade of IVH and volume of punctate WMI. Data analysis occurred between December 2016 and January 2018. Final multivariable analyses examining the association of chorioamnionitis with motor and cognitive outcomes accounted for academic center and perinatal and postnatal factors. PunctateWMI volume and IVH detected on neonatalMRI scans were used tomeasure the results,withmotor and cognitive outcomes defined using Bayley III assessments conducted among these children between 18 and 24 months' CA. There were 448 preterm infants (24-32 weeks' gestation) in the total cohort. Infants were included in the analysis if they had undergone placental pathologic assessments, early brainMRI, and 18 to 24 months of follow-up.Among the cohorts fromthe 3 academic centers, infants with evidence of a congenital infection, genetic syndrome, or large parenchymal hemorrhagic infarction (>2 cm) were excluded. Each placenta was sent fresh for macroscopic and microscopic analyses, which were conducted using the same clinical protocols at each center. Histologic chorioamnionitis was defined by clinical pathologists using strict criteria and the degree of placental inflammation was scored

Association of Histologic Chorioamnionitis with Perinatal Brain Injury and Early Childhood Neurodevelopmental Outcomes among Preterm Neonates

Acute chorioamnionitis refers to the neutrophilic inflammation of the placental tissues thought to result from an ascending bacterial infection. It is considered a major factor associated with pretermbirth and has been estimated to occur in 40%to 80% of preterm deliveries. Chorioamnionitis is associated with several adverse neonatal outcomes, including respiratory distress syndrome, sepsis, bronchopulmonary dysplasia, and death. Clinical studies examining brain injury and neurodevelopmental outcomes among infants with chorioamnionitis have yielded inconsistent results. Most of these studies have focused on intraventricular hemorrhage (IVH) and cystic periventricular leukomalacia. Because the incidence of cystic periventricular leukomalacia has greatly decreased during the past decades concurrent with improvements in neonatal intensive care, punctate white matter injury (WMI) is increasingly recognized as the most prevalent pattern of brain injury among preterm neonates. The researchers performed a prospective cohort study conducted across 3 academic centers in Canada, the Netherlands, and the United States. Children who were born preterm (24-32 weeks' gestation) and who had undergone a placental pathologic evaluation, magnetic resonance imaging (MRI) as soon as clinically stable, and Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley III) assessments between 18 and 24 months' corrected age (CA) were included. Magnetic resonance imaging scans were assessed for grade of IVH and volume of punctate WMI. Data analysis occurred between December 2016 and January 2018. Final multivariable analyses examining the association of chorioamnionitis with motor and cognitive outcomes accounted for academic center and perinatal and postnatal factors. PunctateWMI volume and IVH detected on neonatalMRI scans were used tomeasure the results,withmotor and cognitive outcomes defined using Bayley III assessments conducted among these children between 18 and 24 months' CA. There were 448 preterm infants (24-32 weeks' gestation) in the total cohort. Infants were included in the analysis if they had undergone placental pathologic assessments, early brainMRI, and 18 to 24 months of follow-up.Among the cohorts fromthe 3 academic centers, infants with evidence of a congenital infection, genetic syndrome, or large parenchymal hemorrhagic infarction (>2 cm) were excluded. Each placenta was sent fresh for macroscopic and microscopic analyses, which were conducted using the same clinical protocols at each center. Histologic chorioamnionitis was defined by clinical pathologists using strict criteria and the degree of placental inflammation was scored

Association of histologic chorioamnionitis with perinatal brain injury and early childhood neurodevelopmental outcomes among preterm neonates

IMPORTANCE Understanding the role of chorioamnionitis, a major factor leading to preterm birth, in the pathogenesis of neonatal brain injury and adverse neurodevelopmental outcomesmay help in identifying potentially modifiable perinatal variables affecting brain health and outcomes among children born preterm. OBJECTIVE To evaluate whether histologic chorioamnionitis among neonates born very preterm is associated with intraventricular hemorrhage (IVH) and punctate white matter injury (WMI) or with adverse neurodevelopmental outcomes during early childhood. DESIGN, SETTING, AND PARTICIPANTS Prospective cohort study conducted across 3 academic centers (from April 2006 to September 2013 in Canada, from March 2007 to March 2013 in the Netherlands, and from January 2004 to August 2011 in the United States). Children who were born preterm (24-32 weeks' gestation) and who had undergone a placental pathologic evaluation, magnetic resonance imaging as soon as clinically stable, and Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) assessments between 18 and 24 months' corrected age (CA) were included. Magnetic resonance imaging scans were assessed for grade of IVH and volume of punctate WMI. Data analysis occurred between December 2016 and January 2018. Final multivariable analyses examining the association of chorioamnionitis with motor and cognitive outcomes accounted for academic center and perinatal and postnatal factors. MAIN OUTCOMES AND MEASURES Punctate WMI volume and IVH detected on neonatal magnetic resonance imaging scans; motor and cognitive outcomes defined using Bayley-III assessments conducted among these children between 18 and 24 months' CA. RESULTS Of 350 neonates (182 male) in the final cohort, 145 (41.4%) had histologic chorioamnionitis. Gestational age was significantly lower among those with chorioamnionitis (median, 26.4 weeks; interquartile range [IQR], 25.6-27.7 weeks) than among those without chorioamnionitis (median, 28.0 weeks; IQR, 27.0-29.7 weeks). Chorioamnionitis was not associated with IVH or WMI, nor was it associated with worse motor outcomes in univariable or multivariable analyses (adjusted Bayley-III motor score, -2.2; 95%CI, -5.6 to 1.3). Cognitive scores were marginally yet statistically significantly lower among children with chorioamnionitis (median, 105; IQR, 95-110) than among those without chorioamnionitis (median, 105; IQR, 100-115) in the univariable model. This difference was attenuated in the multivariable model (adjusted Bayley-III cognitive score, -3.0; 95%CI, -6.4 to 0.4). CONCLUSIONS AND RELEVANCE Histologic chorioamnionitis was not associated with IVH or WMI near birth or with worse cognitive or motor outcomes from 18 to 24 months' CA after accounting for perinatal factors. Postnatal factors attenuated the association between chorioamnionitis and neurodevelopmental outcomes, highlighting the importance of preventing postnatal illness, such as infection, to promote optimal outcomes among children born preterm