Diagnosis of chronic endometritis: How many CD138+ cells/HPF in endometrial stroma affect pregnancy outcome of infertile women?

Problem The definition of chronic endometritis (CE) differs among studies, and currently, there is no accepted consensus. This study aimed to establish the minimum number of immunohistochemical analysis of CD138+ plasma cells to identify a clinically relevant CE. Method of study We performed a retrospective study on 716 infertile patients who never did CE analysis and respective antibiotic treatment before. Samples were obtained by endometrial scratching in the mid‐luteal phase before IVF‐ET treatment. The number and distribution of CD138+ cells were analyzed by immunohistochemistry. Thirty high‐power fields (HPF) were evaluated for each sample. Patients were classified in 2 main groups: (a) CD138low (