Non-persistent environmental chemical mixture and gestational hypertension, blood pressure, and blood pressure trajectories during pregnancy

• The non-persistent chemical mixture was associated with adverse maternal BP outcomes. • Adverse BP outcomes comprised increased GH risk, higher BP, and rising trajectories. • BADGE-H 2 O, BADGE-2H 2 O, and 6PPD-Q emerged as key contaminants in multiple outcomes Gestational blood pressure (BP) is susceptible to exogenous exposures, including environmental chemicals. However, epidemiological evidence is lacking, particularly for the emerging contaminants. We quantified 31 urinary chemicals in early-pregnancy among 815 women from the Jiashan Birth Cohort in Zhejiang Province, China. We applied logistic regression, generalized estimating equation and Bayesian kernel machine regression (BKMR) models to analyze associations between 16 frequently detected compounds and gestational hypertension (GH), trimester-specific BP levels, and BP trajectories throughout pregnancy. Bisphenol A (2,3-dihydroxypropyl) glycidyl ether (BADGE-H 2 O), bisphenol A-bis(2,3-dihydroxypropyl) ether (BADGE-2H 2 O), and N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-Q) were consistently associated with an increased risk of GH, elevated BP levels across all trimesters, and a greater likelihood of belonging to BP trajectory groups with a rising pattern. BKMR confirmed that the mixture exposure was associated with higher BP values across all trimesters, identifying BADGE-H 2 O as the predominant contributor. Bisphenol A (BPA) and 2-methylthio-benzothiazole (2-Me-S-BTH) also showed associations with elevated BP levels and altered BP trajectory membership, whereas inverse associations were preliminarily observed for propyl paraben (PrP), benzyl paraben (BzP), and 2-(Isopropylamino)-5-(phenylamino) cyclohexa-2,5-diene-1,4-dione (IPPD-Q). This study reported novel associations between early-pregnancy exposure markers of non-persistent chemicals, especially emerging contaminants (BADGE-H 2 O, BADGE-2H 2 O, and 6PPD-Q), and adverse maternal BP outcomes. These findings highlight the potential public health concern posed by these widespread environmental exposures, and underscore the importance of considering real-world mixture exposures. Further research is needed to validate these associations and to elucidate the underlying biological mechanisms.