Purpose of the study – to improve the methods of prevention, diagnosis and treatment of patients with history of early reproductive loss. Materials and methods. During 2010–2017 study of the endometrium of women of reproductive age with an early history of reproductive loss (4-12 weeks) was performed. In the process of preparation for the next pregnancy, an evaluation of anti-inflammatory therapy was carried out after elimination of hormonal violations, genetic diseases and at least 3 months after the end of the last pregnancy. Ultrasound examination of the pelvic organs, histological and microbiological examination of the endometrium was carried out on the 7-10th and 21-24th days of the menstrual cycle.The contingent of studies was determined by retrospective analysis of the case histories of 360 women with spontaneous abortion in gestational terms from 5 to 12 weeks. Depending on the form of abortion, the groups were selected: 1 (n=72) – anembryonia, 2 (n=192) – embryo lysis, 3 (n=96) – frozen pregnancy on a background of the inflammatory process in the uterus.The control group consisted of 30 patients with artificial abortions, planning a future pregnancy. Results and discussion. As a result of a retrospective analysis of histological studies of scrapers, various abnormalities in the development of pregnancy in the early period were observed. At the stage of preparation for pregnancy, an ultrasound evaluation of the structure of the endometrium in 100 women was performed. Among them, in group 1 there were 17 women who had anembryonia in anamnesis. Sonographically, the structure of the endometrium had some peculiarities: in 13 (76.47%) cases, it satisfied the criteria for the 1st and 2nd phases of the menstrual cycle. Four women in the first stage had a hyperechoic structure of the basal layer, a decrease in the thickness of the endometrium (up to 6.3 mm) in the 2nd phase of the menstrual cycle and asymmetry (23.5%). All patients underwent bacteriological and PCR studies of aspiration materials from the uterus. Conditionally pathogenic microorganisms were detected in 24.2%, a combination of mycoplasma and ureaplasma in 15.2%, a combination of mycoplasma, ureaplasma and viruses in 12.1%, aero-anaerobic associations in 12.1%, a combination of chlamydia and viruses in 61% cases.The study allowed to conduct etiopathogenetic treatment on the basis of changes revealed in each specific case.In patients with a predominance of viral and infectious factors, the immunomodulator was administered into the uterine cavity up to 5 ml every 2 days, No. 5.The choice of the antibacterial drugs depended on the microbiological data.After the end of anti-inflammatory and immunomodulatory therapy, the microflora of the genital tract was restored by administering probiotics for 3 weeks. The duration of therapy was 4 weeks. Cyclic hormone therapy or only progestins in the II phase of the cycle was carried out for 2-3 cycles.Two months after the treatment, the control of its effectiveness was monitored. In the last cycle, the state of the endometrium was evaluated (ultrasound and hemodynamic dopplerometry of the uterus).As a result, the frequency of detection of the correspondence of the endometrium to the echographic structure during the secretory phase of the cycle was brought to the values of the control indices of healthy women of childbearing age.Evaluation of the restoration of fertility was carried out 6 months after the examination and treatment. The frequency of occurrence and progression of pregnancy for 12 weeks in the first group was 5 (29.41%) cases compared with 18 (47.36%) in group 2, 15 (27.27%) in group3. Conclusion. Chronic endometritis is a clinical and morphological syndrome, which is determined by ultrasonic criteria, and the morphological picture isequally important part of the diagnosis. Hysteroscopy can be considered as the final diagnostic method for establishing the pathology of the endometrium. Our results show a high percentage of chronic inflammation of the uterine cavity in patients with early reproductive losses.The results of hysteroscopic, microbiological and ultrasound studies can individualize therapeutic tactics. Conducted morphological studies demonstrated a high informative value of biopsy in the diagnosis of endometrial pathology.