Molecular pathways and immune microenvironment regulation in stem cell therapy for thin endometrium: a comprehensive narrative review.

A thin endometrium is a significant contributor to female infertility and adverse pregnancy outcomes and remains a persistent challenge in reproductive medicine. Stem cell therapy, when integrated with biomaterials and tissue engineering, has emerged as a promising approach for thin endometrial repair. This review systematically summarizes the critical molecular pathways involved in stem cell-based therapy for thin endometrium and explores the regulatory mechanisms within the immune microenvironment. This review focuses on the role of stem cells and their exosomes in promoting angiogenesis, exerting antifibrotic effects, and modulating immune responses. The integration of advanced biomaterials is also discussed, highlighting their fundamental roles in optimizing the stem cell transplantation microenvironment and facilitating endometrial regeneration. This review integrates recent insights into the molecular mechanisms and immune regulation to provide a theoretical framework and clinical guidance for precise therapies targeting thin endometrium.