Integrated Analysis of Preterm Birth and Socioeconomic Status with Neonatal Brain Structure

Abstract

Importance: Preterm birth and socioeconomic status (SES) are associated with brain structure in childhood, but the relative contributions of each during the neonatal period are unknown. Objective: To investigate associations of gestational age (GA) and SES with neonatal brain morphology, by testing 3 hypotheses: GA and SES are associated with brain morphology; associations between SES and brain morphology vary across the GA range, and; associations between SES and brain structure/morphology depend on how SES is operationalized. Design: Cohort study, recruited 2016-2021. Setting: Single center, UK. Participants: 170 preterm infants and 91 term infants with median (range) birth GA 30+0 (22+1-32+6) and 39+4 (36+3-42+1) weeks, respectively. Exclusion criteria: major congenital malformation, chromosomal abnormality, congenital infection, cystic periventricular leukomalacia, hemorrhagic parenchymal infarction, post-hemorrhagic ventricular dilatation. Exposures: Using linear ridge regression models, we investigated associations of GA and SES, operationalized at the neighborhood-level (Scottish Index of Multiple Deprivation), family-level (parental education and occupation) and subjectively (WHO Quality of Life), with regional brain volumes and cortical morphology. Main outcomes/measures: Brain volume (85 parcels) and 5 whole-brain cortical morphology measures (gyrification index, thickness, sulcal depth, curvature, surface area) at term-equivalent age. Results: In fully adjusted models, GA associated with a higher proportion of brain volumes (22/85 [26%], β range |-0.13| to |0.22|) than neighborhood SES (1/85 [1%], β=0.17). GA associated with cortical surface area (β=0.10 [95% confidence interval (CI) 0.02-0.18]) and gyrification index (β=0.16 [95% CI 0.07-0.25]); neighborhood SES did not. Family-level SES associated with the volumes of more parcels than neighborhood SES, but it did not have as extensive associations with brain structure as GA. There were interactions between GA and both family- and subjective-level SES measures on brain structure. Conclusions/relevance: In a UK cohort, GA and SES impact neonatal brain morphology, but low GA has more widely distributed effects on neonatal brain structure than neighborhood-level, family-level and subjective measures of SES. Further work is warranted to elucidate the mechanisms embedding GA and level-specific SES in early brain development.

Association of Preterm Birth and Socioeconomic Status With Neonatal Brain Structure

“…We included 85 individual regional brain parcels (including white matter, gray matter, and CSF spaces) and 5 whole-cortex measures (GI, thickness, sulcal depth, curvature, and SA), as defined by the dHCP . This was due to previous literature providing evidence for regional volumetric changes in association with SES in childhood . Based on reports of SES–brain structure correlations when the brain is characterized using larger parcellations, we analyzed associations of GA and SES with whole brain volume, lobar regional volumes, and lobar cortical measures.…”

“…29 SIMD rank was chosen as the primary measure of SES because it correlates with child development 30 and is a tractable tool for policy makers. 28 Other SES measures were investigated in exploratory analyses, as specified in our preregistered statistical plan 31 : maternal and paternal education, maternal and paternal occupation, and subjective SES (eMethods in Supplement 1 ). Ethnicity data were collected, as there are relationships between ethnicity and SES.…”

“… 41 This was due to previous literature providing evidence for regional volumetric changes in association with SES in childhood. 31 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 Based on reports of SES–brain structure correlations when the brain is characterized using larger parcellations, we analyzed associations of GA and SES with whole brain volume, lobar regional volumes, and lobar cortical measures.…”

Cerebral Small Vessel Disease: Early-Life Antecedents and Long-Term Implications for the Brain, Aging, Stroke, and Dementia

“…Socioeconomic disadvantage in childhood shapes neurodevelopmental and health outcomes from birth onward. 78,79 In childhood, brain structure mediates the relationship between SES and measures of function (eg, language, attention, and memory). 80 Children from higher SES households have access to more social and economic resources, which promote healthy development including cognitively stimulating home environments, healthier nutrition, and more stable living conditions.…”

“…Measurement often varies between studies, and if only 1 measurement is considered, it may not always capture the full socioeconomic position of the individual. 79 Furthermore, SES is not stable across the life course, with upward and downward mobility. Socioeconomically disadvantaged children who experience upward mobility in adulthood have better health outcomes than other disadvantaged children with static or downward mobility, suggesting upward mobility can compensate for disadvantage in childhood.…”