Acquired thrombophilic states are common causes of thrombosis and other forms of pregnancy-associated complications. A growing body of evidence is available to guide the use of anticoagulants in patients who have antiphospholipid antibodies; unfortunately, the results of these studies are conflicting, and solid, evidence-based treatment recommendations cannot be made. Other forms of acquired thrombophilia are uncommon or of unknown clinical significance. Treatments aimed at mitigating the impacts of these states lack clear evidence to support their use.