The first step is to review the indication for anticoagulation and ensure it is evidence based. If so, then decide if a therapeutic or prophylactic level of anticoagulation is required. Due to the potential teratogenic effects of Warfarin, a patient should be moved onto low molecular weight heparin in a dose able to achieve the required level of anticoagulation. Depending upon the indication for Warfarin one may also consider adding in low dose aspirin. We also offer planned indiction of labour or timed CS delivery depending upon clinical grounds so we can manage the birth, and reinstate Warfarin postpartum, continuing LMWH until the levels are therapeutic.