Urinary nonpersistent environmental chemicals in pregnancy: Associations with subclinical renal injury and exposure determinants

• Phenols (BPA, NP) were strongly associated with early renal injury markers. • Parabens showed both individual and joint effects on NAG and ACR. • Phthalate mixture exposure increased ACR despite null single-metabolite results. • Personal care products and indoor environments drove major exposure patterns. • Exposure disparities were influenced by sociodemographic and lifestyle factors. Exposure to xenoestrogens—including phthalates, parabens, and phenols—as well as melamine is widespread; however, evidence regarding their combined effects on early renal injury during pregnancy remains limited . We examined associations between urinary concentrations of nine phthalate metabolites, four parabens, two phenols, and melamine and renal injury biomarkers—N-acetyl-β-D-glucosaminidase (NAG) and albumin-to-creatinine ratio (ACR)—among 1,433 pregnant women in Taiwan. Exposure determinants were assessed using structured questionnaires. Individual and cumulative exposure effects were evaluated by using compound-based summed exposure indices and principal component analysis (PCA) to characterize mixture patterns. In single-chemical models, methylparaben, butylparaben, nonylphenol, and bisphenol A were significantly associated with log-transformed NAG and ACR, while melamine was associated with NAG. Compound-based analyses revealed that phenols exhibited the strongest cumulative associations with both renal biomarkers, followed by parabens for NAG. Although individual phthalate metabolites were not significantly associated with renal markers, cumulative phthalate exposure was positively associated with ACR after covariate-adjusted creatinine standardization. PCA identified exposure patterns linked to personal care product use (parabens) and indoor environmental factors (phthalates), with regional variability observed. Phenols showed consistent associations despite uncertainty regarding dominant exposure sources. The stronger effects identified through compound-based and PCA-derived mixture approaches underscore the importance of evaluating hazardous environmental contaminants as complex exposure profiles rather than as single chemicals. Given the heightened physiological susceptibility during pregnancy, these findings support mixture-oriented risk assessment and targeted exposure mitigation strategies to protect maternal renal health.