Associations between parenting and cognitive and language abilities at age 2 depend on prenatal exposure to disadvantage

Objective: To investigate whether parenting and/or neonatal brain volumes mediate the associations between prenatal social disadvantage (PSD) and cognitive/language abilities; and whether these mechanisms vary by level of disadvantage. Study Design: Pregnant women were recruited from obstetric clinics in St Louis, Missouri. PSD encompassed access to social (e.g., education) and material (e.g., income-to-needs, health insurance, area deprivation, and nutrition) resources during pregnancy. Neonates underwent brain magnetic resonance imaging. Mother-child dyads (N=202) returned at age 1 for parenting measures and at age 2 for cognition/language assessments (Bayley-III). Generalized additive and mediation models tested hypotheses. Results: Greater PSD was nonlinearly associated with poorer cognitive/language scores. The relation between parenting and cognition/language was moderated by PSD, such that supportive and non-supportive parenting behaviors only related to cognition/language in children with low PSD. Further, parenting mediations differed by level of PSD, such that both supportive and non-supportive parenting mediated PSD-cognition/language associations in children with low PSD, but not in children with high PSD. PSD-associated reductions in neonatal subcortical grey matter (β=.19, q=.03), white matter (β=.23, q=.02), and total brain volume (β=.18, q=.03) were associated with lower cognition, but they did not mediate PSD-cognition associations. Conclusions: Parenting moderates and mediates associations between PSD and early cognitive and language development, but only in families with lower levels of social disadvantage. These findings, while correlational, suggest that there may be a critical threshold of disadvantage, below which mediating or moderating factors become less effective, highlighting the importance of reducing disadvantage as primary prevention.