〔Abstract〕 This study employs metabolomics to analyze the characteristic biomarkers and metabolic pathways in the serum of pregnant women with positive thyroid peroxidase antibodies (TPOAb) during early preg- nancy . The objective is to explore the relationship between thyroid dysfunction and maternal-fetal health . Methods Early-pregnancy women undergoing antenatal check-ups for thyroid function and antibody testing at our hospital were selected . According to the TPOAb results , participants were categorized into a TPOAb-positive group and a TPOAb-negative group . The serum metabolic profiles were analyzed using liquid chromatography-tandem mass spec- trometry (LC-MS/MS) technology to identify differences between the two groups . The Kyoto Encyclopedia of Genes and Genomes (KEGG) database was utilized for metabolic pathway enrichment analysis of differential metabolites . Results A total of 79 significantly different metabolites were identified in the serum of TPOAb-positive pregnant women compared to the control group , including 20 upregulated and 59 downregulated metabolites . KEGG enrich- ment analysis indicated that these differential metabolites were mainly involved in 21 key metabolic pathways . A- mong the metabolites associated with TPOAb , 31 were identified , with 6 showing positive correlation and 25 show- ing negative correlation . Metabolic pathway enrichment analysis revealed that these differential metabolites were closely related to Glycerophospholipid metabolism , Valine , leucine and isoleucine biosynthesis , Glycosylphosphati- dylinositol (GPI)-anchor biosynthesis , and Glycerolipid metabolism pathways . Conclusion Significant differences in metabolites and their associated metabolic pathways are identified in the serum of TPOAb-positive pregnant women during early gestation , indicating that these metabolite alterations are closely linked to thyroid dysfunction and maternal-fetal health .