The role of prenatal substance exposure and early adversity on parasympathetic functioning from 3 to 6 years of age

Abstract

We employed latent growth curve analysis to examine trajectories of respiratory sinus arrhythmia (RSA) from 3 to 6 years among children with varying levels of prenatal substance exposure and early adversity. Data were drawn from a prospective longitudinal study of prenatal substance exposure that included 1,121 participants. Baseline RSA and RSA reactivity to an attention-demanding task were assessed at 3, 4, 5, and 6 years. Overall, there were significant individual differences in the trajectories of RSA reactivity, but not baseline RSA, across development. Greater levels of prenatal substance exposure, and less exposure to early adversity, were associated with increased RSA reactivity at 3 years, but by 6 years, both were associated with greater RSA reactivity. Prenatal substance exposure had an indirect influence through early adversity on growth in RSA reactivity. Results are in support of and contribute to the framework of allostatic load.

Keywords: allostatic load; early adversity; prenatal substance exposure; respiratory sinus arrhythmia.

FIGURE 1

The effect of prenatal substance exposure controlling for the effect of early adversity on the quadratic growth of RSA reactivity at 3, 4, 5, and 6 years. Higher levels of RSA reflect greater reactivity. Simple slopes were tested at ±1 SD from the mean.

FIGURE 2

The indirect effect of prenatal substance exposure on RSA reactivity through early adversity. Paths are standardized beta coefficients. Unstandardized beta coefficients are presented in parentheses. Covariates include site. Only significant paths are presented for ease of presentation. RSA, Respiratory sinus arrhythmia reactivity; χ²(8) = 7.90, p = .44; CFI = 1.00; RMSEA ≤.001.*p < .05.**p < .01.***p < .001.