The obstetrical complications preeclampsia, intrauterine growth restriction (IUGR), placental abruption and fetal loss are major causes of maternal and fetal morbidity and mortality. Much recent research has focused on to what extent congenital thrombophilia contributes to these obstetrical complications. Combined with the hypercoagulable state of pregnancy, thrombophilia has the potential to induce placental thrombosis and cause placental insufficiency with subsequent obstetrical complications. This article aims to review and discuss published clinical studies of the relationship between congenital thrombophilia and preeclampsia, IUGR, placental abruption and fetal loss. In addition, the few published clinical trials of prophylactic antithrombotic treatment to prevent severe obstetrical complications in thrombophilic women are discussed. The studies have shown variable results evaluated mainly as a result of the limited number of case reports published. However, the strongest association was found to be between congenital thrombophilia and preeclampsia and late fetal loss. Early fetal loss was not found to be associated with congenital thrombophilia. At present, the question remains open as to whether IUGR and placental abruption is directly associated with thrombophilia or mediated through preeclampsia. In conclusion, the associations between congenital thrombophilia and preeclampsia, IUGR, placental abruption and fetal loss only reaches evidence grade 4. Present recommendations and clinical guidelines are thus based on weak scientific proof.