A comparison of the prevalence of chronic endometritis determined by the use of different diagnostic methods in women with and without reproductive failure

Objective: To compare the prevalence of chronic endometritis (CE) when different diagnostic methods are used. Design: Prospective observational study. Setting: University affiliated hospital. Patient(s): Four groups of women were studied, including women with proven fertility (Fertile, n=40), unexplained recurrent miscarriage (RM, n=93), recurrent implantation failure (RIF, n=39) and infertile subjects undergoing endometrial scratch in a natural cycle preceding frozen-thawed embryo transfer (Infertility, n=48). Intervention(s): Endometrial biopsy was performed precisely seven days following LH surge (LH+7). Plasma cells were identified by traditional H&E staining and immunohistochemistry (IHC) for Syndecan-1(CD138). Main Outcome Measure(s): The prevalence of chronic endometritis. Result(s): The use of CD138 epitope is more sensitive than H&E staining in identifying plasma cells. The use of plasma cell count per unit area had the lowest observer variability than that of cell count per 10 randomly chosen HPF or cell count per section. Using this method, the prevalence of CE in women with RM, RIF and Infertility were 10.8%, 7.7%, and 10.4%, respectively, not significantly higher than that of fertile subjects (5.0%). Conclusion(s): Using what may be a new method of plasma cell assessment, it appears that the prevalence rates of CE reported in many earlier studies may have been over-estimated