Prenatal Social Determinants of Health: Narrative review of maternal environments and neonatal brain development

Abstract

The Social Determinants of Health, a set of social factors including socioeconomic status, community context, and neighborhood safety among others, are well-known predictors of mental and physical health across the lifespan. Recent research has begun to establish the importance of these social factors at the earliest points of brain development, including during the prenatal period. Prenatal socioeconomic status, perceived stress, and neighborhood safety have all been reported to impact neonatal brain structure and function, with exploratory work suggesting subsequent effects on infant and child behavior. Secondary effects of the Social Determinants of Health, such as maternal sleep and psychopathology during pregnancy, have also been established as important predictors of infant brain development. This research not only establishes prenatal Social Determinants of Health as important predictors of future outcomes but may be effectively applied even before birth. Future research replicating and extending the effects in this nascent literature has great potential to produce more specific and mechanistic understanding of the social factors that shape early neurobehavioral development. IMPACT: This review synthesizes the research to date examining the effects of the Social Determinants of Health during the prenatal period and neonatal brain outcomes. Structural, functional, and diffusion-based imaging methodologies are included along with the limited literature assessing subsequent infant behavior. The degree to which results converge between studies is discussed, in combination with the methodological and sampling considerations that may contribute to divergence in study results. Several future directions are identified, including new theoretical approaches to assessing the impact of the Social Determinants of Health during the perinatal period.

Figure 1.

A schematic depiction of the domains included in the Social Determinants of Health (SDoH), which include education, health care, neighborhood environments, community context, and socioeconomic status and some of the structural determinants that contribute to SDoH factors. These structural factors, including policy, social hierarchies, and systemic discrimination against marginalized communities, contribute to the prenatal SDoH that mothers experience and contribute to inequity in developmental outcomes.^,

Figure 2.

In the Early Life Adversity and Biological Embedding (eLABE) study sample, data from 280 mother-infant dyads was used by Triplett and colleagues to examine the associations between prenatal social disadvantage (defined by a combination of socioeconomic factors including income, education, insurance status, and healthy eating) and neonatal brain structure. Maternal prenatal disadvantage was negatively associated with cortical gray matter, white matter, subcortical gray matter, and cerebellum volumes. Reproduced with permission from Ref..

Figure 3.

Maternal psychopathology has been studied as a secondary effect of the Social Determinants of Health, as in a study by Posner and colleagues. In this investigation, the functional and structural connectivity of the amygdala in infants whose mothers who experienced prenatal depression (PMD) were compared to those whose mothers had not experienced prenatal depression (N-PMD). Their structural connectivity analyses revealed reduced structural connectivity between the amygdala and ventral prefrontal cortex in infants whose mothers were in the PMD group. Reproduced with permission from.

Figure 4.

In the eLABE study, we have also examined neonatal functional connectivity associated with maternal prenatal social disadvantage as a predictor of subsequent infant behavior. Frontolimbic connectivity between the right amygdala and a large cluster in the ventromedial prefrontal and anterior cingulate cortex, which was positively associated with prenatal social disadvantage, exhibited a sex-specific link to infant externalizing and internalizing scores on the Infant Toddler Social Emotional Assessment (ITSEA) at age 12 months. Increasing frontolimbic connectivity was associated with decreasing externalizing and internalizing scores in female, but not male, infants. Reproduced with permission from.