Chronic endometritis (CE) is characterized by the presence of atypical plasma cell infiltrates (CD138 positive) in the endometrial stroma. Recent analyzes suggest that CE adversely affects fertility by reducing endometrial receptivity, impairing decidualization and uterine contractility, thus increasing the risk of recurrent pregnancy loss and implantation failure. It is likely that a significant proportion of idiopathic infertility cases are due to CE. The diagnosis of CE is a challenge because the clinical examination and transvaginal ultrasonography are considered non-specific. The recent scientific research has been aimed at identifying hysteroscopic CE diagnostic criteria and establishing the compatibility of ultrasonographic, hysteroscopic, histopathological (including the use of immunohistochemical testing with antibodies against human CD138) and microbiological diagnoses. Preliminary literature results suggested that successful treatment of CE with antibiotics could improve live birth rates.

The objectives are as follows:

1. Estimation of the diagnostic congruity of hysteroscopic, histopathological and microbiological diagnoses of CE
2. Estimation of the effectiveness of empirical antibiotic therapy in the treatment of CE, confirmed by normalization of the hysteroscopic appearance of the uterine cavity, normalization of histopathological results of endometrial biopsies and decrease in plasma cell count/1 high power field (HPF)
3. Estimation of the percentage of clinical pregnancies achieved in women subjected to empiric antibiotic therapy for CE vs. in women without treatment. The study group will consist of women of childbearing age subjected to office hysteroscopy due to intrauterine pathologies, AUB, and idiopathic infertility. The prerequisite for hysteroscopy is a normal cervical cytology result, a negative blood pregnancy test, a normal vaginal biocenosis and the first phase of the cycle. During hysteroscopy, the following will be performed: visual inspection of the uterine cavity in search of focal lesions and features of the endometrium suggestive of CE, such as: focal or diffuse hyperemia, micropolyps, stromal edema, then collection of washings from the uterine cavity for microbiological examination (aerobic and anaerobic culture, PCR for Chlamydia, culture for Mycoplasma, Ureaplsma) and excision of the focal lesion or endometrial biopsy. The extracted tissue material will be subjected to standard histopathological examination with hematoxylin and eosin staining. Additional immunohistochemical staining with Monoclonal Mouse Anti-Human CD138 antibodies will be used to detect plasmocytes. The cut-off point for the number of CE-defining plasmocytes will be determined by the Receiver Operating Characteristic (ROC) curve. Women diagnosed with CE will be assigned to 2 arms: 1) ofloxacin 2x200 mg orally for 10 days + metronidazole 1x500 mg vaginally for 10 days, 2) control arm (no treatment). In the third cycle after the primary hysteroscopy, women will undergo a follow-up office hysteroscopy for a visual assessment of the uterine cavity and a follow-up endometrial biopsy. The percentage of women with improvement in the clinical appearance of the uterine cavity, normalization of histopathology and persistent CE in both arms will be determined. Data will be obtained on the results of infertility treatment (obtaining a clinical pregnancy) within 24 months of the procedure or completion of antibiotic therapy.

Inclusion Criteria:

• age 18-45 years
• lack of previous diagnosis and treatment due to suspected pathology of the uterine cavity
• lack of active infection of the reproductive tract

Exclusion Criteria:

• pelvic surgery performed within 6 months preceding the hysteroscopy
• confirmed pelvic endometriosis
• antibiotic or probiotic treatment within 3 months preceding the hysteroscopy