Thromboembolic disorders are still a serious problem in pregnancy and anticoagulants have an important part to play in both treatment and prevention. Use of anticoagulants during pregnancy is challenging due to the potential teratogenic effects and dosing complexities of the various agents and the fact that pregnancy is associated with a hypercoagulable state. Anticoagulant therapy is indicated in pregnancy for the treatment of acute VTE (Venous Thromboembolism) and valvular heart disease, as well as for the prevention of pregnancy-related complications in women with antithrombin deficiency, antiphospholipid antibody (APLA) syndrome, or other thrombophilias, who have had a prior VTE. Anticoagulants, which are available in oral and parenteral forms, interrupt the coagulation cascade to prevent thrombus formation. Oral anticoagulants are fetopathic, but heparins, especially LMWHs (low molecular weight), are the main anticoagulants used in pregnancy. Heparin does not cross the placenta. Dosing depends on the clinical indications and on the agent selected. No method of anticoagulation during pregnancy is entirely free of risk and all management policies must be based on an estimate of risk-benefit ratio in individual patients.