Abstract:Objective To investigate the serum levels of DNA methyltransferase 1 (DNMT1), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), and quiescin sulfhydryl oxidase 1 (QSOX1) in pregnant women with hepatitis B virus (HBV) infection, and their associations with adverse maternal and neonatal outcomes.Methods One hundred and three pregnant women with HBV infection admitted to the Third Affiliated Hospital of Jinzhou Medical University between October 2019 and October 2023 were enrolled as the HBV group. Fifty healthy pregnant women undergoing routine check-ups during the same period served as the control group. The HBV group was further divided into the favorable outcome (n = 84) and adverse outcome (n = 19) subgroups based on maternal and neonatal outcomes. Clinical data and serum levels of DNMT1, TIM-3, and QSOX were compared across groups. Multivariable logistic regression analysis identified factors influencing maternal and neonatal outcomes in pregnant women with HBV infection, based on which a nomogram was constructed. Receiver operating characteristic (ROC) curves assessed the predictive values of serum levels of DNMT1, TIM-3, and QSOX for adverse maternal and neonatal outcomes.Results Serum levels of DNMT1, TIM-3, and QSOX1 were higher in the HBV group than those in the control group (P < 0.05). The adverse outcome group exhibited greater percentage of patients with higher HBV DNA load, and higher levels of TBIL, AST, and ALT than the favorable outcome group (P < 0.05). Serum DNMT1, TIM-3, and QSOX1 levels were also higher in the adverse outcome group than in the favorable outcome group (P < 0.05). Multivariable logistic regression analysis revealed that high HBV DNA load [O^R = 28.257 (95% CI: 2.069, 385.982) ], elevated DNMT1 levels [O^R = 1.316 (95% CI: 1.039, 1.666) ], elevated TIM-3 levels [O^R = 2.249 (95% CI: 1.319, 3.833) ], and elevated QSOX1 levels [O^R = 1.431 (95% CI: 1.151, 1.780) ] were risk factors for adverse maternal and neonatal outcomes in pregnant women with HBV infection (P < 0.05). ROC curve analysis revealed that the combination of serum levels of DNMT1, TIM-3, and QSOX1 for predicting adverse maternal and neonatal outcomes in pregnant women with HBV infection demonstrated an area under the curve of 0.962, with a sensitivity of 94.7% (95% CI: 0.740, 0.999) and a specificity of 90.6% (95% CI: 0.736, 0.917).Conclusion Serum levels of DNMT1, TIM-3, and QSOX1 are elevated in pregnant women with HBV infection and demonstrate good predictive value for adverse maternal and neonatal outcomes.