Metabolomic profiling delineates the role of adenosine in oocyte quality and embryonic development.

Metabolic determinants of oocyte quality and embryonic development remain incompletely understood. Here, we profiled metabolites in human cumulus cells (CCs) and follicular fluid (FF), validated in two mouse models, and integrated transcriptomics with receptor blockade to define mechanisms. In human CCs, adenosine was higher in cycles yielding fewer high-quality embryos and discriminated embryo quality (ROC AUC = 0.75). Conversely, FF adenosine was reduced in the same context. In mice, low-quality oocytes and their associated CCs accumulated adenosine, revealing an intra- vs extracellular disequilibrium. The imbalance aligned with reduced expression of the adenosine transporters ENT1/ENT2 and the gap-junction component CX37. Functionally, supplementation with exogenous adenosine restored early embryonic development from low-quality oocytes, lowering oxidative stress and spindle/chromosome errors via adenosine receptors. Smart-seq2 transcriptomic analysis and functional experiments showed partial normalization of programs governing meiosis and cellular stress responses, including correction of CycB1/Cdc27 (MPF/APC/C) and JNK-linked pathways. Together, we identify adenosine disequilibrium as a metabolic fingerprint of poor oocyte competence and show that receptor-mediated adenosine signaling tunes MPF-related and oxidative stress pathways to rescue developmental potential. These findings provide a mechanistic and translational basis for early prediction and culture optimization in ART.