The association between exposure to polycyclic aromatic hydrocarbons and the risk of premature rupture of membranes

Premature rupture of membranes (PROM) remains a significant clinical challenge. It has substantial socioeconomic impacts. Despite the known toxicity of polycyclic aromatic hydrocarbons (PAH), there is limited epidemiological evidence on their association with PROM in pregnant populations. Our investigation addressed this gap. We analyzed 1717 late-pregnancy women from the Zunyi Birth Cohort, quantifying urinary PAH metabolites as exposure biomarkers. We used logistic regression and restricted cubic spline (RCS) models to examine the individual and nonlinear associations between PAH and PROM. Bayesian kernel machine regression (BKMR) was also used for the mixed association. Logistic regression revealed that the third tertiles of 2-OHFlu, 9-OHFlu, 2-OHPhe, 3-OHPhe, and 9-OHPhe were associated with 1.58-fold (95 % CI: 1.03–2.47), 2.02-fold (95 % CI: 1.3–3.2), 1.83-fold (95 % CI: 1.23–2.75), 1.52-fold (95 % CI: 1.01–2.32), 2.1-fold (95 % CI: 1.38–3.24) higher PROM risks, respectively. RCS regression showed the nonlinear associations between 2-OHFlu (P-nonlinear = 0.040), 9-OHFlu (P-nonlinear = 0.027), and 3-OHPhe (P-nonlinear = 0.020) and the risk of PROM. BKMR further revealed an increasing trend in PROM risk associated with PAH mixture exposure. This study provides epidemiological evidence that exposure to PAH during late gestation may increase susceptibility to PROM. These findings offer empirical reference evidence for implementing targeted environmental interventions in prenatal care. • 1.Urinary PAHs metabolites increase PROM risk in pregnant women. • 2.Nonlinear relationships indicate threshold effects of PAHs metabolites on PROM risk. • 3.Key metabolites 9-OHFlu and 9-OHPhe show high biological relevance in PROM pathogenesis.