PREVENTION AND TREATMENT OF VENOUS THROMBOEMBOLISM IN HIGH RISK SITUATIONS IN PREGNANCY

Abstract

Venous thromboembolism (VTE) is a leading cause of maternal mortality in the western developed world. VTE may present as deep vein thrombosis (DVT) or pulmonary embolism (PE) but if untreated can result in fatal PE. Although fatal PE is clearly the most significant consequence of VTE in pregnancy, DVT also often leads to morbidity related to the development of post-thrombotic syndrome (PTS). Pregnancy is an independent risk factor for VTE and the risk of VTE is 4–10 fold higher in pregnant women than in non-pregnant women of similar age. The puerperium represents a time of even higher risk. It is clear that many additional high-risk situations in pregnancy lower the threshold for thrombosis and warrant measures to prevent VTE and its complications. Risk factors for pregnancy-related VTE may be inherited or acquired. Acquired risk factors may be specifically related to the pregnancy or may have developed prior to pregnancy. Well-documented risk factors for pregnancy-related VTE include delivery by Caesarean section, previous VTE, and inherited or acquired thrombophilia. Other risk factors that have been identified include obesity, multiparity, multiple gestation, pre-eclampsia and medical conditions, such as sickle cell disease, that predispose to VTE. Our ability to diagnose VTE overall is poor as presenting signs and symptoms are extremely varied and unreliable. This is further complicated in pregnancy where signs and symptoms suggestive of VTE are common and invasive testing is more complicated. It is essential that physicians be vigilant in monitoring patients for the development of VTE and maintain a low threshold for considering thromboprophylaxis. Guidelines have recently been published by several medical societies to help with these difficult decisions. In this review the risk factors for the development of VTE in pregnancy will be discussed and guidelines for risk assessment presented. Management of patients who develop VTE in pregnancy is also outlined.