Congenital and acquired thrombophilias are the most common predisposing factors for thromboembolism, but they may also contribute to pathophysiological processes involved in recurrent pregnancy loss, fetal death, intrauterine growth restriction, placental abruption, placental infarction, and pre-eclampsia. The most common thrombophilias are deficiencies of antithrombin III, protein C, and protein S, acquired protein C resistance, genetic mutation encoding for factor V Leiden, prothrombin gene, and inherited hyperhomocysteinemia, and antiphospholipid syndrome. Although adverse pregnancy outcomes are more common in women with thrombophilia, the current evidence does not support routine thrombophilia screening of all pregnant women. Selective thrombophilia screening may be justified in certain group of women, particularly those with a history of thromboembolism. More research is required to confirm or refute the causal link between thrombophilia and abnormal placentation, and assess effectiveness and safety of thromboprophylaxis in pregnant women.