What is being tested?

This test measures the amount of the hormone hCG in your urine or blood. This hormone is usually present only when a woman is pregnant. It starts getting produced by the placenta after the fertilised egg implants in the womb.

Occasionally, women can also get abdominal tumours that produce hCG.

Home pregnancy test kits, which you can buy from supermarkets and pharmacies, test for hCG in the urine. The urine test can detect hCG from around the time of your first missed period.

The blood hCG test may detect pregnancy earlier — from about 1 week after conception.

Why would I need this test?

Your doctor might use the blood hCG test to check if you are pregnant, to confirm a positive urine hCG test or to monitor your pregnancy. The blood test is more sensitive than the urine test and the results can assist your doctor to work out when your baby will be born and discover whether the pregnancy is developing normally or not.

Blood hCG tests are also used to detect or monitor the tumours that produce hCG. If the hCG level goes up, this suggest the tumour is getting bigger. If it goes down, it suggest the tumour is getting smaller.

How to prepare for this test

No special preparation is required.

Understanding your results

Normally, hCG levels rise quickly in early pregnancy. But if something is wrong with the pregnancy, your hCG levels may be higher or lower than expected.

If you have a type of tumour that raises your hCG level, such as a germ cell tumour, your doctor might use the hCG test to see if treatment is working or if the tumour has come back after treatment.

More information

Visit Lab Tests Online website or Pregnancy, Birth and Baby for more information about hCG tests.

Read our ‘Guide to blood testing’ to learn more about blood tests in general with information such as:

• what to consider before having the test
• what happens during a blood test
• results accuracy
• blood tests cost