The use of low-molecular-weight heparin for the management of venous thromboembolism in pregnancy.

Thromboembolic disease is a rare, but important, complication of pregnancy that remains a leading non-obstetric cause of maternal death. The prevention and management of venous thromboembolism (VTE) in pregnant women is a complex area of medicine: a balance must be found between protecting the health of the mother and minimizing the risk to the unborn fetus. Until now, unfractionated heparin has been regarded as the drug of choice for the prevention and treatment of VTE during pregnancy. However, because of its significant side effects (osteoporosis and heparin-induced thrombocytopenia), the inconvenient mode of administration and need for monitoring, unfractionated heparin is now being replaced by low-molecular-weight heparin (LMWH). There is a convincing body of clinical evidence from well-designed studies and prospective case series that supports the efficacy and safety of LMWH in pregnant women. There are also encouraging observations on the efficacy of LMWH in the prevention of severe obstetric complications, which are frequently associated with inherited or acquired thrombophilias. The recently-published guidelines of The American College of Chest Physicians (ACCP), summarized in this review, allows the development of higher clinical standards. However, there is concern over the greater cost of LMWH compared with unfractionated heparin and oral anticoagulants, and cost-effectiveness studies are needed.