Anticardiolipin antibody test
Quick answer: This blood test measures antibodies against cardiolipin, a fat found in cell membranes. It is one of the antiphospholipid antibodies. Doctors usually order it with lupus anticoagulant and beta-2 glycoprotein I tests after unexplained clots or recurrent pregnancy loss.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
- In fertility carePersistent antiphospholipid antibodies are linked to recurrent miscarriage and other pregnancy complications, so they are often checked after repeated losses.
How the test is done
- 1A nurse confirms your details and the IgG and IgM request
- 2A vein on your arm is cleaned
- 3A needle draws a tube of blood
- 4The lab measures cardiolipin antibody levels by immunoassay
What your results can mean
Reading your report
A single positive result is not enough for a diagnosis; doctors usually repeat it at least 12 weeks later and read it with your history.
If the result is outside the usual range
Moderate to high levels on two tests 12 or more weeks apart can point to antiphospholipid syndrome. Low or short-lived levels can follow infections and are often not significant.
Who usually has this test
Women with recurrent miscarriage, stillbirth or early severe pre-eclampsia, and people with unexplained clots or lupus.
Risks and aftercare
A small bruise is possible; no other aftercare is needed.
Names and options
Also called: aCL, ACA, cardiolipin antibody, anticardiolipin IgG, anticardiolipin IgM
Options
- IgA
- IgG
- IgM
Listed by the hospital as
- ANTI CARDIOLIPIN ANTIBODY IGA, SERUM
- ANTI CARDIOLIPIN ANTIBODY IGG, SERUM
- ANTI CARDIOLIPIN ANTIBODY IGM, SERUM
Questions about this test
What does a positive anticardiolipin antibody mean in pregnancy?
Moderate to high levels found on two tests at least 12 weeks apart can point to antiphospholipid syndrome, which is linked to miscarriage and other pregnancy problems. Your doctor will explain whether any treatment is advised.
What is the difference between IgG and IgM anticardiolipin?
They are two classes of the same antibody. IgG has been more closely linked with clots and pregnancy problems, but both are counted in the diagnostic criteria.
Why must the anticardiolipin test be repeated?
Antibodies can rise for a short time after an infection and then disappear. A repeat test at least 12 weeks later shows whether they are persistent, which is what matters for diagnosis.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
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This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.