Seventy-eight women with RIF and/or RPL underwent peripheral blood collection and endometrial biopsy during the mid-luteal phase. Serum AMH levels were quantified using an automated chemiluminescent immunoassay (Beckman Coulter Access). Endometrial RNA was analyzed via targeted sequencing for metabolic (FOXO1, SGK1, SCNN1A, SLC2A1) and NK cell-related genes (Granzyme B [GZMB], IL-15). Protein localization was assessed by immunohistochemistry (IHC) and immunofluorescence (IF), including