Fig. 1. Histological changes in placental villous trees of women with novel coronavirus infection. А. Placenta of women with uncomplicated pregnancies, one terminal villus contains 3–7 vessels; ×40. B. Placenta of women with uncomplicated pregnancies, one terminal villus contains 3–7 vessels 3–7; ×400. C. Placenta of patients with Covid-19; increased fibrinoid deposition; ×100. D. Placenta of patients with Covid-19; focal accumulations of inflammatory cells (macrophages, lymphocytes with a dash of plasmocytes and sporadic neutrophils); ×400. E. Placenta of patients with Covid-19; angiogenesis with predominant vascular branching: capillary number increase in one villus to more than 10 together with blood vessel diameter reduction; intact syncytiotrophoblast membranes attract attention. F. Placenta of patients with Covid-19; angiogenesis with predominant vascular branching: capillary number increase in one villus to more than 10 together with blood vessel diameter reduction. G. Placenta of patients with Covid-19; multiple infarction and hemorrhages in placental samples obtained from women with Covid-19. H. Placenta of patients with Covid-19

Fig. 2. CD4 expression in placental tissue in patients with Covid-19 and comparison group. А. Focal increase in the number of СD4+ macrophages and lymphocytes in the villous stroma in patients with Сovid-19; ×200. B. Focal increase in the number of СD4+ macrophages and lymphocytes in the villous stroma in patients with Сovid-19; ×200. C. Focal increase in the number of СD4+ macrophages and lymphocytes in the villous stroma in patients with Сovid-19; ×400. D. Macrophages СD4+ in the villous stroma in women with uncomplicated pregnancy; ×400

Fig. 3. Placental tissue immunohistochemical analysis using primary antibody to SARS-COV-2. А. Weak syncytiotrophoblast membrane and fibrinoid deposits staining in placental tissue of patients with Covid-19, intact syncytiotrophoblast membrane attracts attention, ×200. B. Weak focal staining of endothelium in individual villous vessels; ×400. C. Weak syncytiotrophoblast membrane and fibrinoid deposits staining in placental tissue of patients with Covid-19, intact syncytiotrophoblast membrane attracts attention, ×200; weak focal staining of endothelium in individual villous vessels; ×400. D. Negative staining. Placenta of women with no history of Covid-19; ×100. E. Prominent positive staining of viral particle accumulations around the perimeter of dystrophic villus. Placenta of a woman with acute leukemia, who died from Covid-19. The fetus died in utero from placental insufficiency at 20 weeks of gestation. Stained inflammatory cells are visible: lymphocytes, macrophages; ×100. F. Prominent positive staining of viral particle accumulations around the perimeter of dystrophic villus. Placenta of a woman with acute leukemia, who died from Covid-19. The fetus died in utero at 20 weeks of gestation from placental insufficiency; ×40

Fig. 4. TNFα expression in placental tissue in patients with Covid-19 and comparison group. А. TNFα expression in placental structures of women with uncomplicated pregnancy, weak staining of syncytiotrophoblast membrane and cytoplasm, as well as of vascular endothelium; no staining of fibrinoid deposits; ×100. B. TNFα expression in placental structures of women with uncomplicated pregnancy, weak staining of syncytiotrophoblast membrane and cytoplasm, as well as of vascular endothelium; no staining of fibrinoid deposits; ×200. C. TNFα expression in placental structures of women with Covid-19. Weak staining of vascular endothelium; positively stained fibrinoid deposits; ×200. D. TNFα expression in placental structures of women with Covid-19. Weak staining of vascular endothelium (Fig. C); as well as of syncytiotrophoblast membrane and cytoplasm, and syncytial knots (Fig. D); positively stained fibrinoid deposits (Fig. C); ×200

Fig. 5. IL8 expression in placental tissue in patients with Covid-19 and comparison group. А. IL8 expression in placental structures of women with uncomplicated pregnancy, weak staining of syncytiotrophoblast membrane and cytoplasm, as well as of vascular endothelium; no staining of fibrinoid deposits; ×100. B. IL8 expression in placental structures of women with uncomplicated pregnancy, weak staining of syncytiotrophoblast membrane and cytoplasm, as well as of vascular endothelium; no staining of fibrinoid deposits; ×200. C. IL8 expression in placental structures of women with Covid-19; IL8 expression in patients with mild forms of the disease: weak staining predominantly in the syncytiotrophoblast membrane and cytoplasm; weak staining of fibrinoid deposits; ×100. D. IL8 expression in placental structures of women with Covid-19; IL8 expression in patients with moderate forms of the disease: more prominent staining of placental structures, mostly in the syncytiotrophoblast; intensively stained fibrinoid deposits; some villi are embedded in fibrinoid deposits; ×400. E. IL8 expression in placental structures of women with Covid-19; IL8 expression in patients with moderate forms of the disease: more prominent staining of placental structures, mostly in the syncytiotrophoblast; intensively stained fibrinoid deposits; some villi are embedded in fibrinoid deposits; ×200. F. IL8 expression in patients with moderate forms of the disease: more prominent staining of placental structures, mostly in the syncytiotrophoblast; intensively stained fibrinoid deposits; some villi are embedded in fibrinoid deposits

Fig. 6. Expression of proinflammatory mediator IL4 in placental villi in patients with Covid-19 and comparison group. А. IL4 expression in placental structures of women with uncomplicated pregnancy; weak staining of syncytiotrophoblast and villous vessel endothelium; ×100. B. IL4 expression in placental structures of women with uncomplicated pregnancy; weak staining of syncytiotrophoblast and villous vessel endothelium; ×400. C. IL4 expression in placental structures of women with Covid-19: decreased staining is visible. D. IL4 expression in placental structures of women with Covid-19: decreased staining is visible