White matter microstructure and gray matter density in 12-year-old preterm born children.

Abstract

Background: To investigate white matter microstructure and gray matter densities in 12-year-old children born very preterm and evaluate potential effects of antenatal steroids and intraventricular hemorrhage (IVH).

Methods: Brain MRI (3Tesla) was performed in 57 children born very preterm, 16 with IVH and 41 treated with antenatal corticosteroids, and in 22 full-term controls. White matter microstructure and gray matter density were compared between groups using tract-based spatial statistics (TBSS) and voxel-based morphometry (VBM).

Results: Preterm-born children showed no differences in white matter fractional anisotropy (FA) compared to controls, but showed increased or decreased gray matter density in several regions. In the preterm group, lower gestational age was associated with reduced FA in the anterior commissure and the anterior parts of the inferior fronto-occipital fasciculus. Antenatal steroid exposure did not affect FA or gray matter density. IVH was associated with decreased gray matter density in the temporo-occipital cortex.

Conclusion: Very premature birth is associated with alterations in gray matter density, and there is a correlation between gestational age and white matter integrity. Antenatal steroid exposure does not affect white matter integrity or gray matter density, but IVH exposure is associated with locally decreased gray matter density.

Impact: Prematurely born adolescents show differences in gray matter density in several regions compared to controls, with both increased and decreased values observed. In prematurely born adolescents, there is a correlation between lower gestational age and reduced white matter integrity. Assessment of white matter microstructure using tract-based spatial statistics (TBSS) and gray matter volumes using voxel-based morphometry (VBM) in the same cohort of subjects shows alterations in regions involving the same neural circuit.