Indirect Coombs test (ICT)
Quick answer: The indirect Coombs test checks your blood plasma for antibodies that could attack red blood cells, such as anti-D. It is done before blood transfusions and in pregnancy, especially for Rh-negative women.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed; tell staff if you have had an anti-D injection.
- In fertility careIn an Rh-negative pregnancy it shows whether the mother has made antibodies that could affect the baby, which guides anti-D and monitoring.
How the test is done
- 1Blood is drawn from your arm into the tube the lab needs
- 2Your plasma is mixed with test red cells
- 3A reagent shows whether antibodies have bound to them
- 4If positive, the lab identifies the antibody and may measure its level
What your results can mean
Reading your report
A positive result is usually followed by tests to name the antibody and measure its level; discuss it with your doctor.
If the result is outside the usual range
A positive result means antibodies against red cells are present, such as anti-D, which can affect a baby in pregnancy or a future transfusion. A negative result means no such antibodies were found.
Who usually has this test
Pregnant women, especially those who are Rh negative, and anyone before a blood transfusion.
Risks and aftercare
Bruising is possible; if you are Rh negative, keep track of when anti-D injections are due.
Names and options
Also called: ICT, indirect antiglobulin test, antibody screen, IAT
Listed by the hospital as
- ICT (INDIRECT COOMBS TEST)
Questions about this test
Why do Rh-negative pregnant women need an ICT?
The test checks whether the mother has made antibodies against Rh-positive blood. If the test is negative, doctors can offer anti-D injections to prevent this. If it is positive, the pregnancy is watched more closely.
Does an anti-D injection affect the ICT result?
Yes. Anti-D given in pregnancy can show up on the test for some weeks. Tell staff when you had your last anti-D injection so the result is read correctly.
Is the ICT repeated during pregnancy?
Rh-negative women are usually tested early and again later in pregnancy. If antibodies are found, testing becomes more frequent.
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 →
Reception
Waiting area
IVF lab
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.