Background: Arterial thrombosis is uncommon in pregnancy but may have devastating consequences. The incidence of ischemic stroke associated with pregnancy is estimated to be about 4.2 to 210 per 100 000 deliveries. Mortality level is very high and is 8-26%. Events occur most frequently in the III trimester of pregnancy or postpartum. Pregnancy is a kind of an essential spontaneous screening test for the risk of early stroke in women and augments the risk of stroke in 3-13%. Methods: We observed 59 patients with history of arterial thrombotic complications and 60 healthy pregnant women. Among 59 women 4 of them had stroke and VTE, 3 had myocardial infarction, 2 patients – acute arterial cerebral thromboembolism and thrombosis of prosthetic heart valves. Some women had history of stroke and ileo-femoral thrombosis and splenic infarction and thrombosis occurred in different other localizations (n=16, 27.1%) including combination of ischemic stroke and retinal thrombosis, deep vein thrombosis, Takayasu syndrome and renal thrombosis, subclavian artery thrombosis, avascular necrosis of the femoral head and reoccurred cerebral thromboembolism in patients with catastrophic antiphospholipid syndrome. I subgroup consists of 20 patients with history of arterial thrombosis. All these women were enrolled into the study from the fertile cycle or from the beginning of pregnancy andd therapy was started early. II subgroup accepted 17 patients from II or III trimesters of pregnancy and therapy was started after their admission. Thrombosis was associated with pregnancy in 17 women (28.8%). The remaining 22 patients with arterial thrombosis had thromboembolic complications during current pregnancy. All included patients had been examined for the hemostasis system abnormalities. Results: Risk factors included SLE, vasculitis, metabolic syndrome, hypertonic diseases, cardiac arrhythmia, the presence of prosthetic heart valves, inadequate anticoagulant therapy, open foramen ovale, intake of OC, surgery interventions, septic complications, vertebrobasilar abnormalities. The examination demonstrated the high frequency of genetic and acquired froms of thrombophilia and high level of resistance to protein C in patients with arterial thrombotic events. Different forms of thrombophilia were present in 88.2% of patients. Multigenic thrombophilia was recorded in 84,3% of patients, fibrinolytic defects in 76.5% patients, APA in 41.2%, and hyperhomocysteinemia in 19.6%. Comment: The revelation of the multigenic thrombophilia, fibrinolytic defects and APA circulation indicates an essential role of thrombophilia in the genesis of thrombotic complications. Early pathogenic anticoagulant therapy with LMWH, antiaggregant drugs, antioxidants, vitamins group B from the fertile cycle when a women start to plan a pregnancy allows prevent reoccurred thrombotic events, severe obstetric complications and improve perinatal outcomes.