Chronic Endometritis: Diagnostic Considerations in Patients With Infertility

Abstract

Chronic endometritis (CE) is a controversial clinical and pathological entity. Although the presence of plasma cells (PCs) is the most frequently used diagnostic criterion for CE, the minimal diagnostic criteria remain controversial and undefined. The clinical setting of CE (asymptomatic, pelvic inflammatory disease, infertility) is an important consideration regarding the clinical significance of endometrial PCs. In the setting of infertility, specifically recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL), CE may have a negative impact on endometrial receptivity, resulting in higher rates of implantation failure. The proposed pathophysiology is that a subclinical intrauterine infection alters the local inflammatory milieu resulting in a shift of the normal inflammatory cell profiles toward responses associated with implantation failure and poorer reproductive outcomes. Cure rates following antibiotic treatment are reported to be high (up to 90%). The results of meta-analyses describing the effect of CE on reproductive outcomes are mixed. There is evidence supporting CE as a treatable factor with improved reproductive outcomes following treatment and there are also results showing no differences in reproductive outcomes. Variable diagnostic criteria for CE, inclusion criteria, and treatment regimens between studies are the main limitations, hampering the ability to compare results across studies. Results regarding the optimal diagnostic criteria in the setting of RIF and RPL are also variable, with some authors recommending a cutoff of 1 or more CD138+ PCs per high-power field and some recommending a cutoff of 5 or more CD138+ PCs per high-power field. There are some studies indicating CE as a negative prognostic factor in patients with RIF and RPL, which may be reversible with antibiotic treatment. The optimal diagnostic criteria for CE in this clinical setting are undefined. For the investigation of infertility patients whom clinicians intend to treat, a descriptive diagnosis (indicating the presence/number of PCs and method of identification) is a reasonable approach. Routine use of CD138 immunohistochemistry is of limited value for the diagnosis of CE.