Description
Recurrent Miscarriage Thrombotic Profile
Recurrent Miscarriage Thrombotic Profile is a batch of blood tests looking for thrombotic risk factors such as Antiphospholipid Antibody Syndrome (APLS) in women who have had a miscarriage or recurrent miscarriage. Treatment with Heparin (Clexane, Tinzaparin, Enoxaparin), Aspirin or Folic Acid may improve the outcome in a subsequent pregnancy.
Female : 2 Purple, 4 Gold, 3 Blue, 1 Green Vacutainer
The profile includes:
1) Lupus Anticoagulant and Anticardiolipin Antibodies (APLS or antiphospholipid antibody syndrome) – please note that both will need to be repeated 6 or more weeks later
2) Extended thrombophilia screen to include Methyl TetraHydroFolate Reductase (MTHFR), Factor V Leiden, Prothrombin 2 Mutation, Protein C, Protein S, Antithrombin III.
Click here to learn more about Antiphospholipid Antibody Syndrome and its effects on fertility, miscarriage, pregnancy and general health!
What about Patients on Warfarin or Low Molecular Weight Heparin?
When interpreting thrombophilia or antiphospholipid antibody screens, anticoagulation therapy like Warfarin or low molecular weight heparin (LMWH) can affect certain components of the tests. Here’s a breakdown of which components remain valid and which may be affected in these scenarios:
1. For a Patient on Warfarin (Vitamin K Antagonist):
Warfarin affects tests that depend on vitamin K-dependent clotting factors, particularly Protein C and Protein S, as well as functional assays.
Valid Components on Warfarin:
• Antiphospholipid Antibody Testing:
• Anticardiolipin Antibodies (IgG, IgM)
• Anti-β2-Glycoprotein I Antibodies (IgG, IgM)
• Lupus Anticoagulant (with caution)
• Lupus anticoagulant (LA) testing may be affected as Warfarin prolongs clotting times. However, LA can still be tested using special techniques like a dilute Russell viper venom test (dRVVT) corrected for prolonged INR.
• Genetic Thrombophilia Tests:
• Factor V Leiden Mutation (DNA test)
• Prothrombin G20210A Mutation (DNA test)
• MTHFR Mutation (DNA test)
• Antithrombin III (ATIII):
• Typically unaffected by Warfarin.
Components Likely Invalid or Affected on Warfarin:
• Protein C and Protein S Levels:
• Warfarin reduces Protein C and Protein S levels (both are vitamin K-dependent), making these tests unreliable while the patient is on Warfarin.
• Testing should be deferred until Warfarin is stopped for at least 2–3 weeks.
• Activated Protein C Resistance (APCR):
• APCR may also be unreliable in the presence of anticoagulation therapy. Genetic testing for Factor V Leiden is preferred.
2. For a Patient on Low Molecular Weight Heparin (LMWH):
LMWH, unlike Warfarin, mainly inhibits Factor Xa and thrombin, and its effects are more limited to clotting cascade activity. However, it can interfere with certain functional assays.
Valid Components on LMWH:
• Antiphospholipid Antibody Testing:
• Anticardiolipin Antibodies (IgG, IgM)
• Anti-β2-Glycoprotein I Antibodies (IgG, IgM)
• Lupus Anticoagulant (LA)**:
• Testing may be valid if LMWH is stopped 24 hours before sampling (to avoid interference with clot-based assays).
• Genetic Thrombophilia Tests:
• Factor V Leiden Mutation (DNA test)
• Prothrombin G20210A Mutation (DNA test)
• MTHFR Mutation (DNA test)
• Protein C and Protein S Levels:
• LMWH does not affect these levels, so testing is valid.
• Antithrombin III (ATIII):
• LMWH typically does not alter ATIII levels, so testing is valid.
Components Likely Invalid or Affected on LMWH:
• Lupus Anticoagulant (LA):
• LMWH may interfere with clot-based functional tests such as the dRVVT or aPTT-based LA tests. Testing is more reliable if LMWH is withheld for 24 hours before sampling.
Practical Recommendations:
Timing: For both Warfarin and LMWH, some tests are best performed after discontinuation of anticoagulation therapy. Warfarin requires a washout period of 2–3 weeks, whereas LMWH may require only a 24-hour break.
Alternative Approaches: Genetic Testing (Factor V Leiden, Prothrombin mutation) and antibody-based tests (anticardiolipin and anti-β2-glycoprotein) remain unaffected by anticoagulants and can be reliably performed at any time.
Bridging Therapy: In high-risk patients, anticoagulation can be briefly switched to LMWH to facilitate testing for Protein C and Protein S after stopping Warfarin.
Always consult with a haematologist or specialised lab for the most accurate interpretation of results in anticoagulated patients.
