Extending non-targeted exposure discovery of environmental chemical exposures during pregnancy and their association with pregnancy complications, a cross-sectional study

BackgroundNon-targeted Analysis (NTA) methods identify novel exposures; however, few chemicals have been quantified and interrogated with pregnancy complications. ObjectivesWe characterize levels of nine exogenous and endogenous chemicals in maternal and cord blood identified, selected, and confirmed in prior NTA steps including: linear and branched isomers perfluorooctane sulfonate (PFOS); perfluorohexane sulfonate (PFHxS); monoethylhexyl phthalate; 4-nitrophenol; tetraethylene glycol; tridecanedioic acid, octadecanedioic acid; and deoxycholic acid. We evaluate relationships between maternal and cord levels and the relationship gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy in a diverse pregnancy cohort in San Francisco. MethodsWe collected matched maternal and cord serum samples from 302 pregnant people at delivery from the Chemicals in Our Bodies cohort in San Francisco. Chemicals were identified via NTA and quantified using targeted approaches. We calculate distributions and Spearman correlation coefficients testing the relationship of chemicals within and between the maternal and cord blood matrices. We used logistic regression to calculate the odds of GDM and hypertensive disorders of pregnancy associated with an interquartile range increase in maternal chemical exposures. ResultsWe detected linear PFOS, PFHxS, octadecanedioic acid, and deoxycholic acid in at least 97% of maternal samples. Correlations ranged between -0.1 and 0.9. We observed strong correlations between cord and maternal levels of PFHxS (coefficient = 0.9), linear PFOS (0.8), and branched PFOS (0.8). An IQR increase in linear PFOS, branched PFOS, and octadecanedioic acid is associated with increased odds of GDM [OR (95%CI): 1.43 (0.96, 2.14), 1.56 (1.00, 2.44), and 1.26 (0.83, 1.92) respectively] and tridecanedioic acid positively associated with hypertensive disorders of pregnancy [1.28 (0.90, 1.86)]. DiscussionWe identified both exogenous and endogenous chemicals, two of which (octadecanedioic acid and tridecanedioic acid) have both endogenous and exogenous sources, and which have seldom been quantified in pregnant people or related to pregnancy complications.