Prenatal Substance Exposure and Child Self-Regulation: Pathways to Risk and Protection

Both the human and animal literature suggests that prenatal cocaine exposure (PCE) has the potential to significantly alter the regulatory system. However, not all PCE children exhibit regulatory problems and the association between PCE and self-regulation may occur through different developmental pathways. Understanding these pathways to risk or resilience and moderators of these pathways has significant implications for content and timing of preventive interventions among children with PCE. We examined a conceptual model for the association between PCE and child self-regulation via maternal harshness from 7 to 24 months and child language development at 3 years. Environmental risk, autonomic reactivity in infancy, and child sex were hypothesized moderators. The sample consisted of 216 mother-child dyads recruited at birth and assessed periodically at 2, 7, 13, 24, 36, and 48 months of child ages. PCE was assessed using a combination of maternal self-report, maternal hair, and maternal and infant urine assays for cocaine. Maternal harshness was coded during mother-infant/toddler play interactions at 7, 13, and 24 months. Two indices of self-regulation, effortful control and internalization of rules of conduct or conscience were assessed using observational measures at 3 and 4 years of age. Structural Equations Modeling (SEM) was used to examine the fit of the conceptual model and hypothesized indirect pathways, with multiple group models testing moderation. Results indicated a significant indirect association between PCE and child effortful control at 3 years via higher maternal harshness in the infant/toddler period, B = -.24, 95% CI [-.52, -.01].  Environmental risk did not moderate the PCE and self-regulation association, but there was significant moderation by child sex. For boys, higher cigarette exposure was associated with lower self-regulation (β = -.30, p < .05), but the association was opposite for girls. Autonomic reactivity in infancy moderated the association between maternal harshness and self-regulation, such that among infants displaying a maladaptive increase or no change in autonomic reactivity in response to frustration, higher maternal harshness was associated with lower conscience at 3 years (β = -.27, p < .05), while this path was non-significant for children exhibiting an adaptive decrease in RSA from baseline to frustration. Results indicate that the quality of caregiving experience plays a significant role in the development of self-regulation among PCE children, especially those who are more biologically vulnerable in infancy.  Past pregnancy, preventive interventions should focus on reducing maternal harshness and promoting strategies for fostering self-regulation in the infant/toddler period.