HBsAg (hepatitis B surface antigen) test
Quick answer: An HBsAg test checks your blood for the surface protein of the hepatitis B virus. A positive result usually means you currently have hepatitis B infection. Doctors order it to screen for hepatitis B in pregnancy, before IVF or surgery, and when liver tests are abnormal.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
- In fertility careThis is one of the standard infection screening tests done for both partners before IVF and early in pregnancy. If a mother is positive, the baby can be protected with vaccine and immunoglobulin at birth.
How the test is done
- 1You sit and a band is tied around your upper arm
- 2A nurse cleans a vein inside your elbow
- 3A needle draws blood into a tube
- 4The sample is tested for hepatitis B surface antigen, sometimes first on a rapid card
What your results can mean
Reading your report
A rapid card result is usually confirmed by a lab method, and a positive result needs follow-up tests with your doctor.
If the result is outside the usual range
A positive result usually means hepatitis B virus is in your blood, either as a new infection or a long-term one. A negative result means the surface antigen was not found, though very early infection can be missed.
Who usually has this test
Both partners before IVF, all pregnant women, people before surgery or dialysis, and anyone with jaundice or abnormal liver tests.
Risks and aftercare
Nothing special for the blood test; if positive, your doctor will arrange further hepatitis B tests.
Names and options
Also called: HBsAg, Australia antigen, hepatitis B test, HBsAg card test, HBsAg CLIA
Options
- Australia antigen, serum
- Australia antigen screen
- Card (rapid) test
- CLIA
Listed by the hospital as
- AUSTRALIA ANTIGEN, SERUM
- AUSTRALIA ANTIGEN (HBS AG), SCREEN
- HBSAG, CARD TEST
- HBSAG CLIA, SERUM
- HBSAG, SERUM BY CLIA
Where this test fits in fertility care
- 1Fertility work-up
- 2Screening before IVF or IUIThis test
- 3During treatment
- 4After embryo transfer
- 5Pregnancy check-ups
- 6If treatment has not worked
The usual order. See every test at each stage →
Questions about this test
Is Australia antigen the same as hepatitis B?
Yes. Australia antigen is an older name for HBsAg, the hepatitis B surface antigen. A positive result means hepatitis B virus is present in your blood and needs follow-up with your doctor.
Why is HBsAg tested before IVF?
Fertility guidance recommends screening both partners for hepatitis B, hepatitis C and HIV before treatment. This protects you, your baby and others, and lets the lab handle samples safely. A positive result does not usually stop IVF but needs specialist care.
If my HBsAg is positive, can my baby be protected?
Yes, in most cases. Babies born to mothers with hepatitis B are given the hepatitis B vaccine and immunoglobulin soon after birth, which greatly lowers the chance of infection. Your doctor may also suggest medicine late in pregnancy if your viral load is high.
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.