Abstract
PURPOSE: To evaluate whether the inflammatory proteomics of uterine fluid is feasible in defining the endometrial receptivity phase. METHODS: Inflammatory proteomics of uterine fluid was measured using the OLINK Target-96 Inflammation panel. Endometrial receptivity testing (ERT) combined with endometrial dating was used to define the phase of endometrial receptivity. A predictive model based on proteomics of uterine fluid was established to predict the endometrial receptivity phase. RESULTS: The inflammatory factors in uterine fluid were differentially expressed between the window of implantation (WOI) and displaced WOI groups; the displaced WOI group was characterized by increased expression of a variety of inflammatory factors. The predictive model established based on the top five differential proteins could classify the endometrial receptive phase. Transcriptomic data from endometrial tissues showed that the differential gene sets between different receptive phases were mostly enriched in immune-related processes, and the expression of immune-related genes in the WOI group was significantly lower than that in the displaced WOI group. CONCLUSIONS: Detecting inflammatory proteins from the uterine fluid using the OLINK inflammation panel is feasible and holds promise as a novel non-invasive method to define endometrial receptivity phases.