Introduction: Pregnancy is a normal physiological state that predisposes to thrombosis, which is caused by the hormonal changes in the maternal body. These ones are represented by the change of the blood flow (venous stasis), by changes in the vessel wall (hypotonia, endothelial lesions), changes in the coagulation factors (increased levels of factor VII, factor VIII, factor X, von Willebrand factor), and by the decrease in the natural anticoagulants level (protein C, protein S). In this study, we aimed to establish a possible association between thrombosis and hereditary thrombophilia in pregnant women with this pregnancy - related pathology. Thrombosis during pregnancy is a serious complication that requires excellent cooperation between obstetrician and anesthetist. The second purpose of our study was to monitor the incidence of IUGR in these women. Intrauterine growth restriction is a major cause of fetal morbidity and mortality during pregnancy. At present, the role of the factor V Leiden mutation, of the prothrombin gene mutation, and of the MTHFR gene mutation as risk factors for IUGR is not clearly established. Material and methods: Retrospective study - 161 pregnant women with a history of thrombosis, intrauterine growth restriction, preeclampsia, recurrent miscarriages, who were admitted to the "Cuza Vodă" Maternity in Ia'i, between 2015 and 2017, and on whom genetic tests for thrombophilia were carried out. We monitored the risk of thrombosis and the prevalence of maternal thrombophilia in the group of pregnant women who had IUGR as well. Results: In comparison with a control group, the following were found: the risk of thrombosis in patients with factor V Leiden mutation is higher, pregnant women with a family medical history of thrombosis have a higher risk of thrombosis, the prevalence of hereditary thrombophilia is 3 times higher in the group of pregnant women who also have IUGR, the frequency of the MTHFR gene mutation and of protein S is higher in the IUGR group, and there is no significant connection between the factor V Leiden mutation and preeclampsia or IUGR. Conclusion: This study demonstrates that the protein S deficiency and the MTHFR gene mutation are more common in IUGR pregnancies. No significant association was found between the factor V Leiden mutation and preeclampsia or between factor V Leiden and IUGR. The risk of thrombosis in patients with mutation in the factor V gene was 2.52 times higher than in patients who didn't have this mutation. [ABSTRACT FROM AUTHOR]