Here this small article will help you: Three fourths of cases of venous thrombosis occur antepartum, with approximately 50% occurring by week 15 of gestation. Deep venous thrombosis (DVT) begins in veins of the calf and thigh in pregnancy, as it does in nonpregnant women, but a striking propensity exists for involvement of the left lower extremity. The clinical diagnosis of DVT is more difficult in pregnant women than in nonpregnant women because swelling and leg discomfort are common in pregnancy. A 30-years population-based study collated the cases of deep venous thrombosis or pulmonary embolism in women during pregnancy or the postpartum period. The relative risk was 4.29 and the overall incidence of venous thromboembolism (absolute risk) was 199.7 per 100,000 woman-years. Among postpartum women, the annual incidence was 5 times higher than the pregnant women (511.2 vs 95.8 per 100,000). The incidence of deep venous thrombosis was 3 times higher than that of pulmonary embolism (151.8 vs 47.9 per 100,000). Pulmonary embolism was relatively less common during pregnancy versus the postpartum period (10.6 vs 159.7 per 100,000) (Heit, 2005). NOW IT S UP TO YOU TO DECIDE.