The Role of Opportunistic Microorganisms in the Etiology of Chronic Endometritis in Women of Reproductive Age

Objective. To assess potential role of opportunistic microorganisms in the etiology of chronic endometritis by comparison of microbiota of upper and lower genital tract in women of reproductive age with different histopathologic findings of chronic endometritis and endometrial polyps. Materials and Methods. A total of 164 women of reproductive age were enrolled in this study and assigned to four groups by histopathologic changes in endometrium: I — complete set of chronic endometritis findings (n=38); II — partial set of chronic endometritis findings (n=92); III — endometrial polyps (n=15); IV — control group (n=19). An endometrium biopsy and fine-needle aspiration biopsy was performed during the hysteroscopy in 60 and 104 female patients, respectively. Comparative analysis of vaginal microbiota and endometrial microorganisms was completed by culture. Results. Endometrial colonization with opportunistic microorganisms was found in 56.7% of women with chronic endometritis. The most common microorganisms isolated were streptococci (23.7%), primarily S. agalactiae and S. anginosus followed by Gardnerella vaginalis (15.8%), enerobacteria and enterococci (13% each). Anaerobes and actinomyces were found less frequently (5.2% each). Odds ratio (OR) for endometrial colonization in women with altered vaginal microbiota was determined to be higher than in patients with normal vaginal microbiota (OR=3.5, p<0.01, 95% CI 2.2–5.6). Women with chronic endometritis and altered vaginal microbiota had the highest OR for endometrial colonization (OR=10.4, p<0.01, 95% CI 1.5–70.6). Conclusions. The association between alterations in vaginal microbiota and endometrial colonization with opportunistic microorganisms has been determined. In most cases, endometrial infection occurred in women with vaginal infections being the risk factor of ascending infection.