Making better embryos—not more: omics-guided lessons to redesign in vitro systems

In vitro embryo production (IVP) has achieved remarkable gains in efficiency; however, these advances are still based on oversimplified models. By optimizing blastocyst yield rather than biological quality, the field has systematically overlooked the critical reality that embryos reaching the blastocyst stage in vitro frequently exhibit profound molecular and functional deviations from their in vivo counterparts, with measurable consequences for implantation success, placental function, and long-term offspring health. Current IVP systems continue to impose non-physiological conditions during the most epigenetically vulnerable windows of preimplantation development. Converging evidence from omics technologies demonstrates that in vitro environments do not merely stress the embryo; they probably rewire its regulatory architecture. Disruptions in metabolic flux alter the epigenome, and redirect gene expression networks, thereby reducing developmental fidelity and generating molecular signatures consistent with the Developmental Origins of Health and Disease (DOHaD) concept. A central limitation is the prevalence of descriptive omics studies that describe molecular differences without establishing causal mechanisms. Advancing embryo quality requires a shift toward functional perturbation approaches, multi-omics integration, and mechanistically based experimental design. In this review, we propose a conceptual model for next-generation IVP systems built on adaptive culture conditions responsive to embryo-derived metabolic signals, restoration of epigenetic integrity, and re-establishment of bidirectional embryo-environment communication through oviductal signals, extracellular vesicles, and bioengineered interfaces. Success metrics must be redefined from blastocyst formation to functionally validated outcomes. The future of IVP lies not in producing more embryos, but in producing embryos whose molecular architecture reflects the regulatory precision of the beginning of life.