Prenatal substance exposure and early childhood adversity: implications for child autonomic functioning at early school-age

INTRODUCTION: We examined associations between prenatal tobacco exposure (controlling for other substance exposures) and autonomic functioning at early school-age via infancy autonomic regulation, harsh parenting, and cumulative postnatal adversities. METHODS: 216 mothers (74% Black/African-American) and infants (51% girls) recruited at delivery were assessed repeatedly. Prenatal substance exposure was measured using multiple biomarkers and calendar-based interviews. Harsh parenting and early childhood adversity were assessed from birth to early school-age. Child ANS functioning was indexed via respiratory sinus arrhythmia (RSA) and skin conductance (SCL) at early school-age (both at rest and reactivity to frustration). RESULTS: Prenatal tobacco and cannabis exposure accounted for unique variance in higher baseline SCL and RSA, respectively. Prenatal tobacco exposure was also indirectly associated with lower baseline SCL and blunted SCL reactivity via increased early childhood adversity. There was stability in baseline RSA from infancy to early school-age with prenatal cocaine exposure and prenatal cannabis exposure associated with lower baseline RSA in infancy. Prenatal cocaine exposure was also associated with higher baseline SCL and higher SCL reactivity via more harsh parenting. CONCLUSIONS: Findings highlight unique direct and indirect effects of prenatal tobacco exposure on child ANS functioning at early school-age, controlling for exposure to other substances and co-occurring risks. Results underscore the importance of smoking cessation interventions in pregnancy that address prenatal polysubstance use. IMPLICATIONS: The present study adds to the sparse literature on effects of prenatal tobacco exposure on autonomic nervous system functioning controlling for other substance exposure and co-occurring postnatal risks in a prospective design. Findings highlight the importance of smoking cessation treatments for pregnant individuals who use other substances in addition to tobacco. Furthermore, universal parenting interventions may promote positive outcomes even in the context of substance use. Efforts to address parents' mental health and provide parental support in the context of substance use may be of great benefit to families.