Multi-omics analysis reveals steroid hormone biosynthesis as a key pathway in advanced maternal age threatened abortion†

Advanced maternal age (≥35 years) is increasingly common and associated with a higher risk of threatened abortion, yet its molecular basis remains unclear. To elucidate the underlying mechanisms of advanced maternal age-related threatened abortion (AMA-TA) by integrating metabolomics and transcriptomics. Untargeted serum metabolomics was performed in nine AMA-TA patients and seven age-matched healthy pregnant women. An AMA-TA mouse model was established using mifepristone (4 mg/kg) to assess embryo resorption, placental morphology, and serum hormone levels. Serum metabolomics and placental transcriptomic profiling (RNA-seq) were then conducted in AMA-TA mice to characterize metabolic and gene expression alterations. Cross-species and multi-omics integration was performed using HomoloGene and MetaboAnalyst 5.0. Key genes were validated by real-time quantitative polymerase chain reaction. Human serum metabolomics revealed the differential metabolites were mainly enriched in steroid hormone biosynthesis, lipid metabolism, and amino-acid metabolism. The AMA-TA model showed higher embryo resorption, abnormal placental architecture, and reduced progesterone and chorionic gonadotropin. RNA-seq revealed 111 up- and 1337 downregulated genes enriched in 68 pathways. Consistently, serum metabolomics in AMA-TA mice also showed significant metabolic disturbances, prominently involving steroid hormone biosynthesis. Integrated analysis converged on steroid hormone biosynthesis as a shared key dysregulated pathway. Real-time quantitative polymerase chain reaction further confirmed aberrant expression of steroid metabolism-related genes, including upregulation of Akr1d1 and UGT family genes. Disruption of steroid hormone biosynthesis represents central molecular feature of AMA-TA. Integrated multi-omics analysis offers mechanistic insight and supports the development of biomarkers and therapeutic targets for AMA-TA.