The association among maternal early life stress, prenatal stress, and offspring epistress scores

Maternal stress (early life stress (ELS) and prenatal stress (PNS)) influence offspring development via the biological embedding of stress. Maternal physiological stress system activation can be inherited by offspring in utero. However, the associations among maternal stress and offspring epigenetic profiles are unclear. This project aims to determine if PNS mediates the association between maternal ELS and offspring DNA methylation (EpiStress scores). A secondary analysis of data from expectant and new mothers (n=129) and their offspring was conducted. Age at sample collection and cell type proportions were highly correlated with offspring EpiStress scores leading to a stratified mediation analysis. Results indicate PNS was not a mediating factor between maternal ELS and offspring EpiStress scores. Maternal ELS negatively predicted newborn- and not infant EpiStress scores. This suggests that the biological embedding of stress from a mother to her newborn is specific to maternal ELS, not prenatal stress.