子宫内膜自然杀伤(uNK)细胞是胚胎植入前内膜和早孕期蜕膜中数量最多的一类免疫细胞。母体的uNK细胞与胎儿的滋养层细胞相邻且相互作用。uNK细胞分泌一系列细胞因子和血管生长因子,调控滋养层细胞入侵并参与子宫螺旋动脉的重塑。uNK细胞数量的增多与反复种植失败(RIF)、复发性流产(RSA)有关。但仍需更多的研究阐明uNK细胞在胚胎种植过程中的具体作用、对内膜容受性的影响,以此作为临床治疗的依据。 Endometrial natural killer (uNK) cells are the largest group of immune cells in the pre-implantation endometrium and early pregnancy decidua. The maternal uNK cells are adjacent and interact with the trophoblast cells of the fetus. uNK cells secrete a series of cytokines and angiogenic growth factors that regulate trophoblast invasion and participate in the remodeling of the uterine spiral arteries. Increased uNK cell numbers are associated with repeated implant failure (RIF) and recurrent spontaneous abortion (RSA). However, more studies are still needed to elucidate the specific role of uNK in embryo implantation and its impact on endometrial receptivity as a basis for clinical treatment.