Metabolic regulation of oocyte maturation and early embryo development in mammals

Metabolism plays a central role in coordinating mammalian oocyte maturation and early embryonic development. The metabolic changes that occur during these stages are essential for the acquisition of developmental competence and successful reproduction. This review summarizes metabolic regulation from oocyte growth and maturation through fertilization and preimplantation development, with particular emphasis on glucose, lipid, and amino acid metabolism, as well as mitochondrial function. We also discuss how metabolic disturbances associated with maternal obesity, ovarian aging, and polyendocrine metabolic ovarian syndrome (PMOS, formerly termed polycystic ovary syndrome, PCOS) impair oocyte quality and embryonic developmental potential. By integrating recent insights from multi-omics, live-cell imaging, and genetic studies, we propose a framework for understanding how metabolism not only supports but also actively governs developmental decisions. We further discuss mechanism-based strategies to restore metabolic balance and improve reproductive outcomes.