Neonatal Brain Volumes and Early Parenting Behavior as Mediators in Associations Between Prenatal Social Disadvantage and Socioemotional Problems in Toddlers.

Background: Social disadvantage has been associated with early socioemotional difficulties. In this study, we examined mechanisms that relate prenatal social disadvantage (PSD) to the development of early socioemotional problems by testing whether these associations were mediated by 1) neonatal brain volumes (BVs) and/or 2) early parenting behaviors.

Methods: Women were recruited early in their pregnancies and followed prospectively. PSD encompassed access to material (e.g., income-to-needs, health insurance, area deprivation, nutrition, education) resources during pregnancy. Shortly after birth, neonates underwent structural magnetic resonance scanning. Mother-child dyads returned for parenting observations at child age 1 year, and parents reported child socioemotional problems (Infant-Toddler Social and Emotional Assessment: externalizing, dysregulation, internalizing) at age 2 years (N = 267; 45% female). Simple and parallel mediation models were used to test hypotheses.

Results: Greater PSD was associated with increased externalizing and dysregulation symptoms at age 2 years. PSD-associated reductions in neonatal BVs (cortical gray matter, white matter, total brain) mediated both PSD-externalizing and PSD-dysregulation associations. The PSD-externalizing association was additionally mediated by early parenting behaviors, particularly nonsupportive parenting behaviors. Thus, for externalizing symptoms, nonsupportive parenting behaviors and mediating brain metrics were examined simultaneously in parallel mediation models. Nonsupportive parenting remained a significant mediator, while neonatal BVs were no longer significant.

Conclusions: PSD-associated brain structural alterations at birth may serve as early risk factors for the development of multidimensional socioemotional difficulties in toddlerhood. However, parenting emerged as a stronger mediator for externalizing problems, lending support to parenting behaviors as key intervention targets for the prevention of externalizing problems during early childhood.