关键词: 反复种植失败, 复发性流产, 子宫内膜, 免疫因素

Abstract: Embryo implantation and development is a complex process of mutual recognition and adaptation between mother and fetus.In this process，trophoblasts express embryonic antigens and secrete cytokines to escape the attack of maternal immune system.The enrichment of characteristic immune cells in decidua forms a unique immune microenvironment at the maternal-fetal interface，which is beneficial to embryo implantation and development.Although the success rate of IVF-ET has been greatly improved in recent years，recurrent implantation failure（RIF）is still a problem that puzzles the development of assisted reproductive technology.That the fetus，as an allograft，is not rejected by the maternal immune system is the key to the establishment and maintenance of pregnancy.Abnormal maternal-fetal immune regulation can cause recurrent spontaneous abortion（RSA），which brings physical and mental and economic burden to the couple.With the development of reproductive immunology，the role of endometrial immune factors in the pathogenesis of RIF and RSA has attracted increasing attention.The immunotherapy also plays an increasingly important role in the treatment of these diseases.This article will expound the molecular mechanisms of endometrial immune factors in RIF and RSA and the current understanding of immunotherapy，in order to provide a reference for future scientific research and clinical treatment.

Key words: repeated implantation failure, recurrent spontaneous abortion, endometrium, immune factors