〔Abstract〕 Objective 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 pregnancy. 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 spectrometry(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 enrichment analysis indicated that these differential metabolites were mainly involved in 21 key metabolic pathways. Among the metabolites associated with TPOAb, 31 were identified, with 6 showing positive correlation and 25 showing negative correlation. Metabolic pathway enrichment analysis revealed that these differential metabolites were closely related to Glycerophospholipid metabolism, Valine, leucine and isoleucine biosynthesis, Glycosylphosphatidylinositol(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.