Trajectories of brain development in school-age children born preterm with very low birth weight

Abstract

Preterm birth (gestational age < 37 weeks) with very low birth weight (VLBW, birth weight ≤ 1500 g) is associated with lifelong cognitive deficits, including in executive function, and persistent alterations in cortical and subcortical structures. However, it remains unclear whether “catch-up” growth is possible in the preterm/VLBW brain. Longitudinal structural MRI was conducted with children born preterm with VLBW (n = 41) and term-born peers participating in the Norwegian Mother and Child Cohort Study (MoBa) (n = 128) at two timepoints in early school age (mean ages 8.0 and 9.3 years). Images were analyzed with the FreeSurfer 5.3.0 longitudinal stream to assess differences in development of cortical thickness, surface area, and brain structure volumes, as well as associations with executive function development (NEPSY Statue and WMS-III Spatial Span scores) and perinatal health markers. No longitudinal group × time effects in cortical thickness, surface area, or subcortical volumes were seen, indicating similar brain growth trajectories in the groups over an approximately 16-month period in middle childhood. Higher IQ scores within the VLBW group were associated with greater surface area in left parieto-occipital and inferior temporal regions. Among VLBW preterm-born children, cortical surface area was smaller across the cortical mantle, and cortical thickness was thicker occipitally and frontally and thinner in lateral parietal and posterior temporal areas. Smaller volumes of corpus callosum, right globus pallidus, and right thalamus persisted in the VLBW group from timepoint 1 to 2. VLBW children had on average IQ 1 SD below term-born MoBa peers and significantly worse scores on WMS-III Spatial Span. Executive function scores did not show differential associations with morphometry between groups cross-sectionally or longitudinally. This study investigated divergent or “catch-up” growth in terms of cortical thickness, surface area, and volumes of subcortical gray matter structures and corpus callosum in children born preterm/VLBW and did not find group × time interactions. Greater surface area at mean age 9.3 in left parieto-occipital and inferior temporal cortex was associated with higher IQ in the VLBW group. These results suggest that preterm VLBW children may have altered cognitive networks, yet have structural growth trajectories that appear generally similar to their term-born peers in this early school age window.

Early cortical maturation predicts neurodevelopment in very preterm infants

“…In our multicentre cohort of VPT infants, cortical maturation metrics at TEA, especially selected metrics of surface area and inner cortical curvature, were independent biomarkers of future intellectual and linguistic ability. Cortical surface area in almost every region of the VPT cortex was positively correlated with cognitive and language scores, which validates and extends previous published findings 7 8 10. Curvature was negatively correlated with cognitive and language scores for large swaths of the brain, and this metric explained a greater amount of variability in Bayley scores than cortical surface area.…”

“…Decreased cortical surface area is a well-established consequence of prematurity 7–13. In this cohort, surface area of nearly every region of the preterm brain correlated positively with cognitive ability, corroborating prior studies 7–10.…”

“…Surface area of the parietal lobe was an independent predictor in both models, with the right being most important for the cognitive model and the left being most important for the language model. Sripada et al also found that reduced left parieto-occipital surface area was associated with lower cognitive scores at early school age in very low birthweight children 10…”

“…They exhibit decreased cortical surface area ,7–13 decreased cortical folding measures— gyrification index 11 14 15 and sulcal depth 11 12 14—and increased curvature of the white matter surface 13. Cortical surface area7 8 10 and sulcal depth16 measured around TEA have shown promise in predicting cognitive outcomes. However, no studies have examined these biomarkers in combination or examined the prognostic value of white matter/inner cortical surface curvature.…”

Cognitive Functions Mediate the Effect of Preterm Birth on Mathematics Skills in Young Children

“…The underlying reason may be maturational delay of brain structures, specifically white matter tracts. In fact, MRI studies of preterm children and full-term controls found that brain development in both groups follows a similar trajectory that is delayed for children who were born preterm (Sripada et al, 2018).…”