Importance: Exposure to early life adversity alters the structural development of key brain regions underlying neurodevelopmental impairments. The extent that prenatal exposure to life adversity alters structure at birth remains poorly understood.
Objective: To determine if prenatal exposure to maternal social advantage and psychosocial distress alters global and regional brain volumes and cortical folding in the first weeks of life.
Design: A prospective, longitudinal study of sociodemographically-diverse mothers recruited in the first trimester of pregnancy and their infants who underwent brain magnetic resonance imaging scan in the first weeks of life.
Setting: Mothers were recruited from local obstetric clinics from 2017-2020.
Participants: Of 399 mother-infant dyads prospectively recruited into the parent study, 280 healthy, term-born infants (47% female, mean postmenstrual age at scan 42 weeks) were eligible for inclusion.
Exposures: Maternal social advantage and psychosocial distress in pregnancy.
Main Measures and Outcomes: Two measures of latent constructs were created using Confirmatory Factor Analyses spanning Maternal Social Advantage (Income to Needs ratio, Area Deprivation Index, Healthy Eating Index, education level, insurance status) and Psychosocial Stress (Perceived Stress Scale, Edinburgh Postnatal Depression Scale, Everyday Discrimination Scale, Stress and Adversity Inventory). Neonatal cortical and subcortical gray matter, white matter, cerebellar, hippocampus, and amygdala volumes were generated using semi-automated age-specific segmentation pipelines.
Results: After covariate adjustment and multiple comparisons correction, greater social disadvantage (i.e., lower Advantage values) was associated with reduced cortical gray matter (p=.03), subcortical gray matter (p=.008), and white matter (p=.004) volumes and cortical folding (p=.001). Psychosocial Stress was not related to neonatal brain metrics. While social disadvantage was associated with smaller absolute volumes of the bilateral hippocampi and amygdalae, after correcting for total brain volume, there were no regional effects.
Conclusions and Relevance: Prenatal exposure to social disadvantage is associated with global reductions in brain volumes and cortical folding at birth. No regional specificity for the hippocampus or amygdala was detected. Results highlight that the deleterious effects of poverty begin in utero and are evident in the first weeks of life. These findings emphasize that preventative interventions to support fetal brain development should address socioeconomic hardships for expectant parents.
Cumulative effects of prenatal-exposure to exogenous chemicals and psychosocial stress on fetal growth: Systematic-review of the human and animal evidence
