Anticoagulation in Pregnancy with History of Thrombosis

Recommended Antepartum Management

For patients with a history of thrombosis, the American College of Chest Physicians recommends anticoagulation with prophylactic or intermediate doses of low molecular weight heparin (LMWH) during pregnancy, followed by postpartum anticoagulation for 6 weeks 1, 2, 3, 4
The decision to use anticoagulation versus clinical surveillance depends critically on the characteristics of the previous thrombotic event, with provoked thrombosis potentially managed with clinical surveillance during pregnancy, while unprovoked or high-risk thrombosis requires antepartum prophylaxis with LMWH 1, 2, 3, 4

The American College of Chest Physicians recommends LMWH as the anticoagulant of choice over unfractionated heparin (UFH) for prevention and treatment of venous thromboembolism (VTE) in pregnancy, with a Grade 1B recommendation 5, 6, 7
LMWH is preferred over vitamin K antagonists during the first trimester (Grade 1A), second and third trimester (Grade 1B), and when delivery is imminent (Grade 1A) 5, 6

All pregnant women with a history of VTE require postpartum prophylaxis for 6 weeks with LMWH at prophylactic or intermediate doses, or vitamin K antagonists with an INR target of 2.0-3.0, with a Grade 2B recommendation 1, 2, 3, 4

For patients with documented thrombophilia, such as antithrombin deficiency, antiphospholipid antibodies, or combined thrombophilia, prophylaxis with heparin during pregnancy is recommended, starting in the first trimester, although the specific recommendation is not graded due to the absence of a citation that is not marked for ignoring 1, 2, 3
For patients with homozygous Factor V Leiden or prothrombin 20210A mutation with a family history of VTE, antepartum and postpartum prophylaxis with LMWH at prophylactic or intermediate doses is suggested, with a Grade 2B recommendation 1, 2, 3

If delivery is planned, LMWH should be discontinued at least 24 hours before induction of labor or cesarean section (or expected time of neuraxial anesthesia) to allow adequate time for anticoagulation to decrease and reduce the risk of hemorrhagic complications, with a Grade 1B recommendation 1, 2, 4

Direct oral anticoagulants (dabigatran, rivaroxaban, apixaban) should not be used during pregnancy, with a Grade 1C recommendation 5, 6, 7
The decision to use clinical surveillance versus pharmacological prophylaxis should be based on the nature of the previous thrombotic event (provoked versus unprovoked) and the presence of thrombophilia, with a recommendation based on the American College of Chest Physicians guidelines 1, 3