Neurodevelopment and brain maturation in late preterm children: insights from the adolescent brain cognitive...

Neurodevelopmental outcomes in late preterm (LP) children, born between 34 and 36 gestation weeks, remain unclear. This study aimed to examine behavioral, cognitive, and multimodal neuroimaging outcomes in children born late preterm compared with children born full term during early adolescence using data from the large U.S.-based Adolescent Brain Cognitive Development Study, with longitudinal mixed-effects models used as the primary analytic framework to evaluate group, timepoint, and group-by-timepoint effects.

Participants aged 9-11 years at baseline were categorized into LP and full-term (FT; ≥40 weeks) groups. Outcomes included behavioral and emotional problems, cognitive function, structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and resting-state functional MRI. Longitudinal mixed-effects models were used as the primary analyses, with Type III tests evaluating group, timepoint, and group-by-timepoint effects. False discovery rate correction was applied within predefined outcome families.

The longitudinal models showed no broad LP-FT differences or group-by-timepoint interactions in behavioral and emotional problems, most cognitive outcomes, cortical thickness, cortical surface area, or resting state functional MRI within-network connectivity. Structural MRI showed group effects in six regional brain volumes, without significant timepoint or group-by-timepoint effects. DTI showed the most prominent findings: significant group effects were observed in selected white matter tract, cortical and subcortical region of interest fractional anisotropy or mean diffusivity metrics, and significant group-by-timepoint interactions were observed in selected DTI metrics.

These findings suggest that late preterm birth is associated with subtle and regionally specific neuroimaging differences during early adolescence, particularly in DTI metrics.