Pregnancy and the puerperium (postpartum period) are well-established risk factors for venous thromboembolism (VTE), which occurs with a prevalence of 1 in 1600 [1-7]. The overlap with symptoms of pregnancy may impair clinical suspicion making diagnosis of VTE more challenging.
VTE can manifest during pregnancy as an isolated lower extremity deep venous thrombosis (DVT) or clot can break off from the lower extremities and travel to the lung to present as a pulmonary embolus (PE) [8-10]. PE is the seventh leading cause of maternal mortality, responsible for 20 to 30 percent of maternal deaths [11-13]. Thus, the detection of DVT during pregnancy is critical to preventing deaths from PE.
The epidemiology, pathogenesis, and diagnosis of DVT during pregnancy and the puerperium will be reviewed here. The epidemiology, pathogenesis, and diagnosis of PE, as well as the prevention and treatment of DVT and PE during pregnancy are discussed separately. (See "Pulmonary embolism in pregnancy: Epidemiology, pathogenesis, and diagnosis" and "Deep vein thrombosis and pulmonary embolism in pregnancy: Prevention" and "Deep vein thrombosis and pulmonary embolism in pregnancy: Treatment" and "Use of anticoagulants during pregnancy and postpartum".)
The overall prevalence of VTE in pregnancy is low. In the United States, VTE is diagnosed during 1 in 500 to 2000 pregnancies (absolute incidence; 0.025 to 0.1 percent) [1-6]. In a retrospective case-control study of 395,335 pregnant women at 24 weeks of gestation, the incidence of VTE was 85 per 100,000 pregnancies . A population-based inception cohort study over a 30 year period detected an overall incidence of VTE of 200 per 100,000 woman-years . DVT was three times more common than PE .
Similar rates are observed in Europe [2,5]. In one retrospective study of over 72,000 deliveries, the incidence of DVT was 0.71 per 1000 deliveries (95% CI 0.5-0.9) with 0.5 (95% CI 0.34-0.66) and 0.21 (95% CI 0.11-0.31) occurring antenatally and postnatally, respectively . The incidence of PE was 0.15 per 1000 deliveries (95% CI 0.06-0.24) with 0.07 (95% CI 0.01-0.13) and 0.08 (95% CI 0.02-0.14) occurring antenatally and postnatally, respectively .