Thromboprophylaxis

Abstract

Pregnancy and the puerperium are known to increase the risk of deep vein thrombosis (DVT) and venous thromboembolism (VTE) [1–3]. The incidence DVT is highest during the puerperium; hence all postpartum women should be instructed about the signs and symptoms and should be examined carefully for any evidence of VTE. Thromboprophylaxis is offered to reduce the risk of VTE and may be in the form of mechanical methods (compression stockings or pneumatic compression devices) or pharmacologic agents (anti-coagulating agents). Screening for and identification of such women who require thromboprophylaxis early during pregnancy or in the preconceptional period reduce the risk of subsequent DVT and VTE [4]. These are women at high risk of VTE and women with prosthetic heart valves, atrial fibrillation, left ventricular dysfunction, cortical venous thrombosis and foetal loss due to anti-phospholipid syndrome. Some factors which add to the risk of VTE are history of VTE in the past, hospitalization and bed rest, caesarean section (CS) and inherited thrombophilia [3–5]. It is possible that some situations develop during the course of pregnancy and puerperium which require thromboprophylaxis. Caesarean section (CS), especially emergency CS, is associated with a higher risk of VTE [4, 6]. Early ambulation and mechanical thromboprophylaxis are usually sufficient to reduce the risk of VTE following CS, and pharmacologic prophylaxis is required only if there are additional risk factors for VTE. Women already on anticoagulant therapy (e.g. for a prosthetic valve) which is to be continued during pregnancy should be switched from oral anticoagulants to a heparin-based regimen as soon as pregnancy is diagnosed in order to avoid potential teratogenic effects of oral anticoagulants. Change from warfarin to LMWH can be done during attempted conception or can be done once pregnancy is confirmed, as long as this switchover is feasible before 6 weeks of pregnancy.