Comprehensive Non-Targeted Analysis of the Prenatal Exposome Reveals Significant Differences in Chemical Enrichment Between Maternal and Fetal Samples

The exposome has been recognized as an important dimension in understanding human disease and complementing the genome but remains largely uncharacterized. We analyzed 295 matched maternal and cord blood samples using non-targeted high-resolution mass spectrometry and characterized exposome features. We compared the chemical enrichment of the maternal and cord blood samples using a similarity network analysis and examined the interactions between the exogenous and the endogenous chemical features using a molecular interaction networks approach. We detected over 700 chemical features in the maternal and cord pairs and we found that maternal samples are more similar in terms of chemical enrichment to their corresponding cord samples compared to other maternal samples or other cord samples. We observed significant associations between 3 poly/perfluoroalkyl substances (PFAS) and endogenous fatty acids in both the maternal and cord samples indicating important interactions between PFAS and fatty acid regulating proteins. To our knowledge, this is the first non-targeted analysis study that uses such large cohort to characterize the prenatal exposome.