Submitted March 28, 2002
Accepted May 13, 2002
How We Manage Venous Thromboembolism During Pregnancy
Shannon M Bates and Jeffrey S Ginsberg*
Department of Medicine, McMaster University, Hamilton, ON, Canada
* Corresponding author; email: batesm{at}mcmaster.ca.
During pregnancy, physiologic and anatomic changes can complicate the diagnosis of venous thromboembolism (VTE) as well as the management of patients with a high risk of, or established VTE. As in non-pregnant subjects, clinical diagnosis of VTE by itself is unreliable and accurate objective testing is essential. Few diagnostic studies of VTE have been performed in pregnant women and, therefore, approaches are largely extrapolated from those used in non-pregnant subjects with modifications to limit the radiation exposure and overcome the limitations of diagnostic testing in pregnancy. Therapy of established VTE during pregnancy consists of therapeutic doses of unfractionated heparin (UFH) or low molecular weight heparin (LMWH), generally given throughout pregnancy subcutaneously and for four to six weeks post partum. A key unresolved issue includes the optimum dosing of LMWH therapy. Maternal warfarin can be safely used post partum since it is safe to use in the breastfed infant of a mother receiving warfarin. Finally, pregnant women with prior VTE (with or without a hypercoagulable state) have an increased risk of recurrent venous thrombosis. A recent study has demonstrated that for women with a single episode of prior VTE many can be managed without anticoagulants. However, for many, anticoagulant therapy with prophylactic UFH or LMWH is a reasonable option.
