Postnatal infection is associated with widespread abnormalities of brain development in premature newborns

Infection is a risk factor for adverse neurodevelopmental outcome in preterm newborns. Our objective was to characterize the association of postnatal infection with adverse microstructural and metabolic brain development in premature newborns. One hundred seventeen preterm newborns (24–32 weeks gestation) were studied prospectively at a median of 32.0 and 40.3 weeks postmenstrual age: MRI (white matter injury, hemorrhage), MR (magnetic resonance) spectroscopy (metabolism) and diffusion tensor imaging (microstructure). Newborns were categorized as having “no infection”, “clinical infection”, or “positive-culture infection.” We compared brain injuries, as well as metabolic and microstructural development across these infection groups. In 34 newborns, clinical signs were accompanied by positive cultures while 17 had clinical signs of sepsis alone. White matter injury was identified in 34 newborns. In multivariate regression models infected newborns had brain imaging measures indicative of delayed brain development: lower N-acetylaspartate/choline, elevated average diffusivity (D(AV)) and decreased white matter fractional anisotropy. These widespread brain abnormalities were found in both newborns with positive-culture infection and in those with clinical infection. These findings suggest that postnatal infection, even without a positive culture, is an important risk factor for widespread abnormalities in brain. These abnormalities extend beyond brain injuries apparent with conventional MRI.