Maternal Lifetime Trauma Exposure, Prenatal Cortisol, and Infant Negative Affectivity

Abstract

Little research has examined the impact of maternal lifetime trauma exposure on infant temperament. We examined associations between maternal trauma history and infant negative affectivity and modification by prenatal cortisol exposure in a sociodemographically diverse sample of mother-infant dyads. During pregnancy, mothers completed measures of lifetime trauma exposure and current stressors. Third-trimester cortisol output was assessed from maternal hair. When infants were 6 months old, mothers completed the Infant Behavior Questionnaire-Revised. In analyses that controlled for infant sex and maternal age, education, race/ethnicity, and stress during pregnancy, greater maternal trauma exposure was associated with increased infant distress to limitations and sadness. Higher and lower prenatal cortisol exposure modified the magnitude and direction of association between maternal trauma history and infant rate of recovery from arousal. The association between maternal trauma history and infant distress to limitations was somewhat stronger among infants exposed to higher levels of prenatal cortisol. The analyses suggested that maternal lifetime trauma exposure is associated with several domains of infant negative affectivity independently of maternal stress exposures during pregnancy and that some of these associations may be modified by prenatal cortisol exposure. The findings have implications for understanding the intergenerational impact of trauma exposure on child developmental outcomes.

Figure 1

Associations between maternal lifetime trauma exposure history and infant negative affectivity (N = 289). Maternal lifetime trauma exposure scores assessed via continuous ratings from the Life Stressor Checklist-Revised (LSC-R). Infant negative affectivity scores assessed via the Infant Behavior Questionnaire-Revised (IBQ-R). Effect estimates represent the estimated mean difference in the IBQ-R score per one unit change in the LSC-R score. Analyses adjusted for maternal stress exposures during pregnancy, assessed via the Crisis in Family Systems-Revised (CRISYS-R) survey, and for infant sex and maternal age, education, and race/ethnicity. ^*p < .05. ^**p < .01.

Figure 2

Associations between maternal lifetime trauma exposure history and infant negative affectivity: Effect modification by prenatal cortisol exposure (N = 194). Maternal lifetime trauma exposure scores assessed via continuous ratings from the Life Stressor Checklist-Revised (LSC-R). Infant negative affectivity scores assessed via the Infant Behavior Questionnaire-Revised (IBQ-R). Prenatal cortisol (continuous ratings) assessed from maternal hair representing the third trimester of pregnancy. Panels depict the association between maternal lifetime trauma exposure and each infant negative affectivity variable as a smooth function of prenatal cortisol (log transformed) estimated from the varying coefficient model (solid line). Dotted bands represent the 95% pointwise confidence bounds for the change in a given infant negative affectivity mean score associated with a one-unit increase in maternal trauma exposure at each value of prenatal cortisol exposure. Areas in which both dotted bands (upper and lower) fall above or below the zero line indicate intervals of prenatal cortisol values with a significant association between maternal lifetime trauma exposure and the specified IBQ-R scale. Analyses adjusted for maternal stress during pregnancy, assessed via the Crisis in Family Systems-Revised (CRISYS-R) survey, and for infant sex and maternal age, education, and race/ethnicity. Global p-values for modification from the varying coefficient models were calculated to test modification across all cortisol levels (i.e., the null hypothesis being that the smooth varying coefficient term is horizontal). The overall effect modification of maternal lifetime trauma history by prenatal cortisol level was significant for Falling Reactivity. ^*p < .05 for test of effect modification.