Abstract
This study aimed to investigate the effect of diagnosis and treatment of chronic endometritis (CE) on the outcome of assisted reproductive technology (ART) with or without repeated implantation failure (RIF). This retrospective analysis included patients who underwent pathological examination for diagnosis of CE at Yamagata University Hospital. The examination was performed for all patients planned for ART with or without RIF. Patients who were examined within 6 months of the first oocyte retrieval or embryo transfer were included. We counted the number of CD138-positive cells within the endometrial stroma in patients' specimens and analyzed the patients' clinical information. Clinical rates of pregnancy and implantation were determined. A total of 80 women met the inclusion criteria: 13 CE-negative patients (17.3%) and 67 CE-positive patients (83.7%). A significant decrease was noted in the CD138-positive cell count between the first biopsy and second biopsy after CE treatment (p < 0.001). In addition, no significant differences were noted in ongoing pregnancy rates between the CE-negative patients and those who underwent CE treatment. The CD138-positive cell counts at first biopsy tended to be lower in each pregnancy group than in the non-pregnancy group. For patients planned to undergo ART, examination for diagnosis of CE with or without RIF could be considered. Pathological CD138-positive cell counts were considered useful for CE diagnosis and treatment decision-making. The study findings suggest the efficacy of antimicrobial agents in CE treatment, contributing to improved pregnancy outcomes.