Signaling Pathways in Human Blastocyst Development: From Molecular Mechanisms to In Vitro Optimization

In recent years, assisted reproductive technology (ART) has developed rapidly with the delay in reproductive age and the rise in infertility rates. During ART, blastocyst quality is a key factor affecting the rate of implantation and clinical pregnancy, and blastocyst formation is dependent on the precise regulation of multiple signaling pathways in preimplantation embryo development. In this review, we systematically analyze the molecular mechanisms of the core pathways, including Hippo, Wnt/β-catenin, FGF, Nodal, and BMP, in blastocyst lineage differentiation and morphogenesis, and assess the feasibility of optimizing in vitro culture by targeting key signaling nodes, as well as provide theoretical support for constructing research models of preimplantation embryos.