From the Guidelines
During pregnancy, it is crucial to test for clotting disorders such as Factor V Leiden mutation, Prothrombin G20210A mutation, Antithrombin deficiency, Protein C deficiency, and Protein S deficiency, as well as Antiphospholipid syndrome, but certain tests like functional assays for Protein S and acquired disorders should be deferred until at least 6-12 weeks postpartum. When considering the management of thrombotic risk, the American College of Chest Physicians recommends antepartum administration of prophylactic or intermediate-dose unfractionated heparin or prophylactic low-molecular-weight heparin combined with low-dose aspirin for women who fulfill the laboratory criteria for antiphospholipid antibody (APLA) syndrome and meet the clinical APLA criteria based on a history of three or more pregnancy losses 1. Key clotting disorders to test for during pregnancy include:
- Factor V Leiden mutation
- Prothrombin G20210A mutation
- Antithrombin deficiency
- Protein C deficiency
- Protein S deficiency
- Antiphospholipid syndrome, through tests for lupus anticoagulant, anticardiolipin antibodies, and anti-beta2 glycoprotein I antibodies However, tests that should be postponed until after pregnancy include:
- Functional assays for Protein S, as levels naturally decrease during pregnancy 1
- Tests for acquired disorders like disseminated intravascular coagulation (DIC) It's also important to note that if a woman is experiencing an acute thrombotic event during pregnancy and requires immediate anticoagulation therapy, definitive testing for inherited thrombophilias may need to be delayed, though initial screening can still be performed, and for pregnant women with no prior history of VTE who are known to be homozygous for factor V Leiden or the prothrombin 20210A mutation and who do not have a positive family history for VTE, antepartum clinical vigilance and postpartum prophylaxis for 6 weeks with prophylactic- or intermediate-dose LMWH or vitamin K antagonists targeted at INR 2.0 to 3.0 is suggested rather than routine care 1.
From the Research
Coagulation Disorders During Pregnancy
The following coagulation disorders can be tested for during pregnancy:
- Factor V Leiden (FVL) mutation 2
- Prothrombin gene G20210A mutation 3, 4
- Antithrombin deficiency 3, 5
- Protein C deficiency 3, 5
- Protein S deficiency 5
- Activated protein C resistance 5
Coagulation Disorders to be Deferred Until Postpartum
There is no clear evidence to suggest that any coagulation disorders must be deferred until postpartum. However, it is essential to note that pregnancy is a hypercoagulable state, and some coagulation disorders may be more challenging to diagnose during pregnancy due to the physiological changes that occur in the coagulation system 6, 3.
Testing for Coagulation Disorders During Pregnancy
Testing for coagulation disorders during pregnancy is crucial, especially for women with a history of venous thromboembolism (VTE) or a family history of thrombophilia 2. The following tests can be performed during pregnancy:
- Prothrombin fragment 1+2 (F1+2) 6
- Thrombin-antithrombin complex (TAT) 6
- D-Dimer 6, 3
- Endogenous thrombin potential (ETP) 6
Importance of Testing and Diagnosis
Diagnosing coagulation disorders during pregnancy is essential to reduce the risk of VTE and other obstetric complications 3, 4. Identifying women at risk for VTE and instituting thromboprophylaxis appropriate to the level of risk remains the key to reducing morbidity and mortality from the condition 4.