Maternal intimate partner violence exposure is associated with differences in cortical structure in 2-to-3-year-old children: A prospective investigation from the Drakenstein Child Health Study (DCHS)

The adverse impacts of psychological stress during pregnancy are well established, with negative outcomes reported for both mothers and children. Intimate partner violence (IPV) represents a significant stressor, with high prevalence in low- and middle-income countries (LMICs). In a high-adversity South African birth cohort, the Drakenstein Child Health Study (DCHS), we prospectively investigated whether maternal exposure to IPV during pregnancy and in the first 2 years was associated with child brain structure at age 2-3 years. Structural magnetic resonance imaging (sMRI) data was analysed from 171 children (n=70 exposed to prenatal IPV; n=55 to postnatal IPV). Regression modelling explored associations between IPV exposures and measures of brain structure derived using FreeSurfer. Voxel- and surface-based morphometry were conducted using Statistical Parametric Mapping to explore differences in cortical architecture. Analyses adjusted for sociodemographic and clinical confounding variables. Both prenatal and postnatal IPV exposure were associated with increased mean cortical thickness (β=0.037, p=0.030, 95% CI [0.004, 0.070], and β=0.041, p=0.023, 95% CI [0.006, 0.074], respectively), when compared to unexposed controls. Exploratory analyses identified a prenatal IPV-by-child sex interaction in right medial orbitofrontal cortex thickness (p=0.025, FWE-corrected); with greater thickness in boys (β= 0.14, p=0.008, 95% CI [0.04 to 0.24]), but not girls (β=-0.04, p=0.44, 95% CI [-0.15 to 0.07]).Early exposure to IPV may impact cortical structure in childhood, with potential sex-specific effects. These results emphasise the importance of addressing IPV as a public health priority to mitigate long-term impacts on child brain development.