Maternal stress during gestation may affect in utero programming of the stress or hypothalamic-pituitary-adrenal axis (HPAA) with consequences for childdevelopment and subsequent disease susceptibility. As crucial epigenetic processes take place during this period, the first eight gestational weeks (early post-conceptional period, EPCP) may represent a critical window of vulnerability. To test this hypothesis we evaluated the relationship between mothers’ EPCP cortisol levels, a biomarker of maternal HPAA activity, and their children’s prepubertal cortisol levels. We quantified cortisol in first-morning urine specimens collected every other day from 22 mothers during the EPCP and daily from their pre-pubertal children for three weeks at age 11 as they started a new school term, a “natural” challenge. We also measured the children’s salivary cortisol response to an experimental stressor. Maternal cortisol levels during specific EPCP weeks were associated with children’s “basal” cortisol levels prior to thestart of school and cortisol responses and habituation to the start of school and the experimental stressor. Some of these associations were modulated by the children’s sex. This is the first study to evaluate the relationship between maternal EPCP cortisol and children’s stress physiology. Our results suggest that EPCP stress may affect HPAA ontogeny and post-natal functioning.
"Variability in maternal cortisol levels during very early gestation is associated with children’s postnatal hypothalamic-pituitary-adrenal axis activity"
Pablo A Nepomnaschy
Faculty of Health Sciences and Human Evolutionary Studies Program
Simon Fraser University
