In recent decades, it has become increasingly clear that mammalian gametes and early embryos are highly sensitive to metabolic substrates. With advances in single-cell sequencing, metabolomics, and bioinformatics, we now recognize that metabolic pathways not only meet cellular energy demands but also play a critical role in cell proliferation, differentiation, and fate determination. Investigating metabolic processes during oocyte maturation and early embryonic development is thus essential to advancing reproductive medicine and embryology. This review highlights the intricate metabolic pathways, particularly glucose metabolism, that drive the transition from oocyte to embryo. These processes involve a complex interaction of signaling pathways, nutrient availability, and environmental factors, with glucose metabolism not only providing essential energy but also offering a variety of metabolic substrates and intermediates that regulate developmental events, influence cell signaling, and impact epigenetic modifications. This article emphasizes that future research will focus on regulating maternal metabolic environments and non-invasive metabolic monitoring of embryonic systems, particularly glucose metabolism, with promising opportunities to improve embryo selection and personalized assisted reproductive technologies, ultimately enhancing fertility treatment outcomes.