To evaluate the proposed criteria in a large sample and in additional subgroups in order to test the validity of the hysteroscopic features widely-accepted as suggestive of CE.

All patients (n: 2675) underwent outpatient hysteroscopy, with the vaginoscopic approach technique. Hysteroscopic features such as, stromal oedema, diffuse or focal hyperaemia, “strawberry aspect”, micropolyposis and endometrial polyps, are often indicate the presence of chronic endometritis. All hysteroscopic features, alone and in combination were applied in 7 (seven) different subgroups of the sample: total sample, women in reproductive age, women with infertility issues/IVF screening, women with history of recurrent miscarriages, menopausal women, and women with hysteroscopic indication of Abnormal Uterine Bleeding (AUB) in women of reproductive age and postmenopausal bleeding (PMB). From each case, endometrial samples were obtained and immunohistochemistry, identifying CD-138, was applied in order to diagnose CE.

A total of 2675 patients were included of which, 1444 women were found with at least one of the proposed hysteroscopic features mentioned above. Stromal oedema, focal or diffuse hyperaemia and “strawberry aspect” in combination with micropolyposis demonstrated higher rates of diagnostic accuracy in the detection of CE correlated to histologic confirmation. Micropolyposis, stromal oedema, focal or diffuse hyperaemia and “strawberry aspect” offer great diagnostic accuracy in the hysteroscopic detection of Chronic Endometritis, regardless reproductive status and/or clinical presentation. Endometrial polyps are not valid hysteroscopic features in cases of suspected CE.

Diagnostic hysteroscopy can accurately diagnose cases of CE, based on stromal oedema, focal or diffuse hyperaemia and “strawberry aspect”, in combination with micropolyposis. In subgroups of infertile women, higher diagnostic accuracy based on the hysteroscopic features mentioned, was more likely to be achieved. Whether endometrial polyps are suggestive of CE, when identified during office hysteroscopy, remains controversial.