Sex Differences in Stress-Induced Cortisol Response Among Infants of Mothers Exposed to Childhood Adversity

Background: Adverse childhood experiences (ACEs) increase risk for mental illness in women and their children, and dysregulation of the hypothalamic-pituitary-adrenal axis may play a role. The impact of ACEs on the hypothalamic-pituitary-adrenal axis may be strongest when ACEs occur prepubertally and in people who are exposed to abuse ACEs.

Methods: To test this, we measured salivary cortisol in 96 mother-infant dyads while mothers were separated from their infants, who were experiencing a laboratory stressor. Mothers completed the Adverse Childhood Experiences Questionnaire; ACEs that occurred prepubertally (pACEs) were measured, and mother-infant dyads were grouped based on maternal pACE history as follows: no pACEs, ≥1 pACEs with abuse, or ≥1 pACEs but no abuse.

Results: Mothers with ≥1 pACEs exhibited decreases in cortisol (relative to preinfant stressor), which differed significantly from the cortisol increase experienced by mothers with no pACEs, regardless of abuse presence (p = .001) or absence (p = .002). These pACE groups did not differ from one another (p = .929). Significant sex differences in infant cortisol were observed in infants of mothers with ≥1 pACEs (regardless of abuse) but not in infants of mothers with no pACEs. When mothers had experienced ≥1 pACEs, males showed decreases in cortisol in response to a stressor whereas females demonstrated increases, and males and females differed significantly when their mothers had ≥1 pACEs with (p = .025) and without (p = .032) abuse.

Conclusions: Regardless of maternal exposure to childhood abuse, in response to a stressor, pACEs were associated with lower cortisol response in mothers and sex differences in 6-month-old infants, with males showing a lower cortisol response than females.