Background

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with poor physical and mental health. Early-life adversity may dysregulate cortisol response to subsequent stress. This study examines the association between patterns of maternal behavior and infant stress response to a challenge. Specifically, we test whether infant exposure to unpredictable maternal sensory signals is related to the cortisol response to a painful stressor.

Method

Participants were 102 mothers and their children enrolled in a longitudinal study. Patterns of maternal sensory signals were evaluated at 6 and 12 months during a 10-min mother-infant play episode. Entropy rate was calculated as a quantitative measure of the degree of unpredictability of maternal sensory signals (visual, auditory, and tactile) exhibited during the play episode. Infant saliva samples were collected for cortisol analysis before and after inoculation at 12 months.

Results

Unpredictable patterns of maternal sensory signals were associated with a blunted infant cortisol response to a painful stressor. This relation persisted after evaluation of covariates including maternal sensitivity and maternal psychological distress.

Conclusions

This study provides evidence that unpredictable patterns of maternal sensory signals are one process through which caregiving affects the function of infant stress response systems.

Objective

Maternal health and wellness during pregnancy are associated with long-term health outcomes in children. The current study examined whether infants of women who participated in a mindfulness-based intervention during pregnancy that reduced levels of stress and depression, increased physical activity, and improved glucose tolerance differed on biobehavioral markers of psychopathological and physical health risk compared with infants of women who did not.

Methods

Participants were 135 mother-infant dyads drawn from a racially and ethnically diverse, low-income sample experiencing high stress. The women participated in an intervention trial during pregnancy that involved assignment to either mindfulness-based intervention or treatment-as-usual (TAU). Infants of women from both groups were assessed at 6 months of age on sympathetic (preejection period), parasympathetic (respiratory sinus arrhythmia), and observed behavioral (negativity and object engagement) reactivity and regulation during the still face paradigm. Linear mixed-effects and generalized linear mixed-effects models were used to examine treatment group differences in infant outcomes.

Results

Relative to those in the intervention group, infants in the TAU group showed a delay in sympathetic activation and subsequent recovery across the still face paradigm. In addition, infants in the intervention group engaged in higher proportions of self-regulatory behavior during the paradigm, compared with the TAU group. No significant effect of intervention was found for parasympathetic response or for behavioral negativity during the still face paradigm.

Conclusions

Findings provide evidence that maternal participation in a short-term, group mindfulness-based intervention during pregnancy is associated with the early development of salutary profiles of biobehavioral reactivity and regulation in their infants. Because these systems are relevant for psychopathology and physical health, prenatal behavioral interventions may benefit two generations.