The features of the hemostatic system in 119 pregnant women with autoimmune thyroiditis, with vary- ing degrees of thyroid dysfunction, were studied. Data from the studies indicate that in pregnant women with thyroid pathology, pathological activation of the hemostatic system occurs, which is one of the causes of obstetric and perinatal complications. In pregnant women with hypothyroidism, these changes manifest themselves in chronic DIC syndrome of the blood, in pregnant women with hyperthyroidism in subclinical DIC form of the blood. For pregnant women with euthyroidism, structural hypo-coagu- lation is definitive.