Decidualization score identifies an endometrial dysregulation in samples from women with recurrent pregnancy losses and unexplained infertility

To study decidualization-associated endometrial factors. Retrospective cohort study to compare endometrial gene expression patterns in women experiencing reproductive failure including recurrent pregnancy loss or unexplained infertility versus fertile controls. University Reproductive Medicine Center. Women experiencing recurrent reproductive failure including recurrent pregnancy loss or unexplained infertility (n = 42) and fertile controls (n = 18). Endometrial biopsy samples were analyzed with targeted ribonucleic acid sequencing via next-generation sequencing. The primary end point measurements were the expression of genes important for endometrial transformation during decidualization measured singly and in a combined/cumulative score approach. The secondary end point measurements were receiver operating curve analysis and comparisons between the specific biomarkers. The comparison revealed differential expression of factors associated with decidualization, tissue homeostasis, and immune regulation: FOXO1, GZMB, IL15, SCNN1A, SGK1, and SLC2A1. A combined evaluation of these 6 signature factors was designated as a decidualization score in which the maximal score was “6” and the minimal was “0”. Among controls, 89% of the samples had a score ≥5 and 11% had a score of “4”. A total of 76% of samples in the patient group had scores ≤4 and 19% had the lowest score of “0”. A decidualization score