Decidualization is a fundamental biological process that transforms endometrial stromal fibroblasts into specialized decidual cells capable of supporting embryo implantation, placental development, and pregnancy maintenance. Human decidualization differs from that of most mammals because it occurs spontaneously during each menstrual cycle under the influence of progesterone and cyclic adenosine monophosphate signaling. This review summarizes current knowledge regarding the cellular, molecular, endocrine, immunological, and stem-cell-mediated mechanisms regulating decidualization. The role of decidual cells in embryo selection, implantation, immune tolerance, angiogenesis, and tissue remodeling is discussed. Furthermore, the clinical implications of defective decidualization in infertility, recurrent implantation failure, recurrent pregnancy loss, endometriosis, preeclampsia, and fetal growth restriction are examined. Advances in transcriptomics, proteomics, and regenerative medicine have revealed complex regulatory networks that govern decidual differentiation and reproductive success. Understanding these mechanisms may facilitate the development of novel biomarkers and targeted therapies for reproductive disorders.
Publication Date: 2026-06-18