Longitudinal Structural and Diffusion Weighted Neuroimaging of Young Children Born Preterm

Children born preterm are at risk for diffuse injury to subcortical gray and white matter. This study’s objective was to examine structural brain development of young children born preterm. Participants were 47 children born preterm (less than 33 weeks gestational age) and 28 children born full-term. None of the children born preterm had significant brain injury. Children received structural and diffusion weighted MRI scans at 5, 6, and 7 years of age. The effect of preterm birth on volume of subcortical gray matter, and volume, fractional anisotropy (FA) and mean diffusivity (MD) of white matter tracts was examined via general linear models. Volumes of thalamus, brain stem, cerebellar white matter, and several cerebral fiber tracts were smaller, and ventricles were larger in children born preterm compared to full-term controls. We found no significant effect of preterm birth on diffusivity measures. Despite developmental changes and growth, group differences were present and similarly strong at all three ages. Even in the absence of significant neonatal brain injury, preterm birth has a persistent impact on early brain development. The lack of a significant birth status by age interaction suggests a delayed developmental trajectory.