Prenatal alcohol exposure and cortisol activity in 19-month-old toddlers: an investigation of the moderating effects of sex and testosterone

Early exposure to stress and teratogenic substances have an impact on brain structures involved in cognition and mental health. While moderate-to-high levels of prenatal alcohol exposure (PAE) have repeatedly been associated with long-term neurodevelopmental deficits, no consensus has yet been reached on the detrimental effects of low-to-moderate PAE on the children's functioning, including the limbic-hypothalamic-pituitary-adrenal axis. The study aims to examine the association between low PAE and cortisol response to unfamiliar situations in 19-month-old children and to determine whether this association was moderated by sex and testosterone levels. Information regarding PAE, cortisol response to unfamiliar situations, and testosterone activity was available in a total of 130 children participating to the Qu,bec Newborn Twin Study (Montr,al, QC, Canada). Mother alcohol consumption during pregnancy was assessed via a semistructured interview conducted when the children were 6 months of age. The contribution of prenatal and postnatal confounds were examined. Disrupted patterns of cortisol activity were observed only in PAE males. Testosterone tended to be negatively associated with the cortisol response, but not for PAE males, suggesting an altered sensitivity to the inhibitory effects of testosterone in these participants. Low levels of PAE were associated with disrupted cortisol activity, and males may be at higher risk. These findings challenge the existence of a "safe level" of alcohol consumption during pregnancy and have public health implications.