Prenatal Environmental Exposure Drives Distinct MicroRNA Patterns in Maternal and Cord Serum: the NEHO cohort

Environmental exposures during pregnancy can influence cross-talk between the maternal and foetal compartments, eliciting distinct yet coordinated adaptive responses at the placental interface. miRNAs act as key mediators, translating environmental stress into post-transcriptional regulatory signals. This study investigates the effects of prenatal exposure, examining associations between essential elements (EEs), persistent organic pollutants (POPs), and circulating miRNA profiles in 95 maternal–cord pairs from the NEHO birth cohort. Single-chemical regression models identified distinct sets of miRNAs altered by EEs orPOPs in the maternal and cord compartments, while mixture analysis (bWQS) confirmed these associations and revealed both shared and compartment-specific miRNA signatures. Pathway enrichment analysis indicated stress- and apoptosis-related responses in mothers and immune and developmental signaling in foetuses. These findings demonstrate that prenatal exposure to chemical mixtures shapes distinct maternal and foetal miRNA responses, highlighting the placenta’s dual role as a selective barrier and active regulatorof foetal programming.