Objective — to estimate the role of Th1, Th17 and Treg of endometrium in pathogenesis of missed and spontaneous abortions. Material and methods. Endometrial tissue of 22 patients with missed abortions, 22 patients with spontaneous abortions and 57 patients of control group (patents with progressive pregnancy, admitted for medical abortions) in 6—10 weeks of gestation was taken by uterine abrasion. Patients with severe extragenital diseases, endocrine disorders and aniphospholipid syndrome were excluded from research. Expression of mRNA of CD4, CD25, as well as Tbet and STAT4 (markers of Th1 lymphocytes), FoxP3 (marker of Treg lymphocytes), STAT3 (marker of Th17 lymphocytes) were estimated by quantitative PCR. Statistical analysis was performed by Mann—Whitney test using Statistica 13,2 («Statsoft», USA). Results. Expression of mRNA of CD25 and STAT4 (marker of Th1) was significantly higher in patients with missed abortion (5,6-fold (p<0.01) and 88,5-fold (p<0.05) accordingly) compared with control group (progressive pregnancy of early stage). Patients with missed abortions had no differences of mRNA expression of Tbet, FoxP3 and STAT3 in endometrium compared with control group. Expression of mRNA of Tbet (marker of Th1 lymphocytes) in endometrium in patients with spontaneous miscarriages was 2,8-fold higher, than in control group (p<0.05). FoxP3 (marker of Treg) in patients with spontaneous miscarriages was 2,5-fold higher, than in control group (p<0.01). Expression of CD4 and STAT3 (marker of Th17 lymphocytes) had no differences in patients with missed and spontaneous abortions and control group. Conclusion. Our data confirm an important role of Th1 shift in pathogenesis of missed and spontaneous abortions. Singnificantly higher levels of Treg markers in endometrium of patients with spontaneous abortions can be a result of prostaglandins production.