Thrombophilia, thrombosis and pregnancy

The risk of venous thromboembolism (VTE) in pregnancy is 0.05-1.8%, six times greater than in the non-pregnant state, and pulmonary embolism remains the most common cause of maternal death. Maternal age, previous history of VTE, Caesarean section and the presence of thrombophilia, significantly increase the risk of VTE. Acquired or hereditary thrombophilia occur in almost two-thirds of women presenting with recurrent miscarriages, pre-eclampsia, intrauterine growth restriction, abruptio placentae, or stillbirth, which are associated with microvascular thrombosis in placental blood vessels. Women with VTE during pregnancy and especially those with thrombophilia require individualized management, based on the type of defect, the family history and the presence of additional risk factors. These factors are important in determining the dose and duration of antithrombotic therapy during pregnancy and the puerperium, and the thromboprophylactic strategy for future pregnancies. Oral anticoagulants are now seldom used during pregnancy because of their significant side effects. Low-molecular-weight heparins (LMWHs) are increasingly replacing unfractionated heparin in the prevention and treatment of VTE during pregnancy. LMWHs have also been shown to be effective in improving the outcome of pregnancy in women with previous obstetric complications.