Thin endometrium, as a core element affecting the success rate of embryo implantation and overall pregnancy rate, has always been a research hotspot in the field of reproductive medicine. This article systematically reviews the latest research trends on the immunological aspects of thin endometrium, with a focus on analyzing the pathways of immune related mechanisms in its pathogenesis, and comprehensively summarizes current feasible intervention strategies, in order to provide scientific guidance for clinical practice. This article first clarifies the concept definition, clinical characteristics, and pathogenic factors of thin endometrium, and deeply analyzes its interaction with key immune cells such as macrophages, T lymphocytes, and NK cells. Meanwhile, the system elucidated the regulatory roles of cytokines such as granulocyte colony-stimulating factor (G-CSF), vascular endothelial growth factor (VEGF), leukemia inhibitory factor (LIF), etc. in the process of endometrial remodeling. In addition, this article systematically introduces the progress of immune regulation therapy, covering traditional drug interventions and new technologies in regenerative medicine. Existing studies have shown that immune system dysfunction can affect endometrial receptivity through various pathways, including Th1/Th2 cytokine imbalance, excessive activation of natural killer cells, abnormal expression of human leukocyte antigens, and regulatory T cell dysfunction. These mechanisms may directly or indirectly lead to insufficient endometrial thickness, ultimately hindering normal embryo implantation. The complex regulatory network composed of immune cells and cytokines plays a key role in the pathogenesis of thin endometrium. In terms of clinical intervention, traditional treatment methods such as estrogen replacement therapy, growth hormone supplementation, pelvic neuromuscular electrical stimulation, as well as regenerative medicine techniques such as local injection of platelet rich plasma, targeted delivery of growth factors, mesenchymal stem cell transplantation, and G-CSF intrauterine perfusion, have all shown varying degrees of improvement effects. These research advances will provide important theoretical support and technical guarantees for improving the reproductive health level of patients with thin endometrium.
