hCG test

The human chorionic gonadotropin (hCG) test is also known as a pregnancy test (Opens in new tab). This test measures the amount of the hormone hCG in your urine or blood.

The hCG test can be used to both confirm and monitor a pregnancy. The hCG hormone is usually present only during pregnancy. The hCG hormone starts being produced by the placenta (Opens in new tab) after the fertilised egg implants (Opens in new tab) in the womb. During pregnancy, the amount of hCG typically doubles every 2 to 3 days. hCG levels can vary widely between individuals.

Home pregnancy test kits check for hCG in your urine. They can usually detect hCG from around the time of your first missed period.

The hCG blood test is more sensitive than the urine test and may detect pregnancy from about 1 week after conception (Opens in new tab). Your doctor may refer you for this blood test to:

• check if you are pregnant
• confirm a positive urine hCG test
• check that your pregnancy is developing normally

If something unusual is happening with your pregnancy (such as unexpected ultrasound results), your doctor may refer you for the hCG blood test to monitor the condition.

Blood hCG tests are also used to detect tumours that can produce hCG, such as testicular cancer and ovarian cancer. Blood hCG tests can monitor these tumours. This can help your doctor check if treatment is working or if the tumour has returned after treatment.

You usually need to go to a pathology collection centre with a referral from your doctor. Your doctor will recommend one near you.

Sometimes, your doctor will collect blood for testing in their clinic. Blood tests are also routinely done in hospitals.

You can buy a home pregnancy hCG urine test from supermarkets and pharmacies.

No special preparation is required for the hCG test.

However, if you are having other blood tests done at the same time, you may need to prepare. Check with your doctor or the pathology collection centre if there is anything you need to do before your blood test.

If you are doing a urine test, try not to drink a lot before the test. This can dilute your urine sample and may cause a false negative result. It is best to do the test first thing in the morning, because your urine is likely to be more concentrated.

Make sure to carefully follow the instructions that are supplied with the test. If you get a negative result but your period still hasn't started, repeat the test in a week's time.

A health professional will take a sample of blood, usually from a vein in your arm. The blood will then be sent to a laboratory for testing.

The hCG urine test can be done at home or at your local health practice. In this test, the urine is mixed with a solution that changes colour if hCG is present. Some tests require you to wee directly onto the test stick. For other tests, you dip the test stick into a sample of your urine.

There are 2 types of results that you can get from your hCG test:

• Qualitative tests, such as the at home pregnancy test, simply tell you if hCG is present or not present in your urine. If hCG is present, this is considered a positive test result (you are probably pregnant).
• Quantitative tests, such as the hCG blood test, measure the actual amount of hCG in your blood.

Normally, hCG levels rise quickly in early pregnancy (Opens in new tab), but in some cases, your hCG levels may be higher or lower than expected. If you are concerned about your hCG test, speak to your doctor.

If you have a tumour, and your doctor suggests using the hCG test to monitor its size:

• an increase in your hCG test result may suggest that the tumour is getting bigger
• a decrease in your hCG test result may suggest that the tumour is getting smaller

False negative result

A false negative result is when the test shows you're not pregnant, but you actually are.

If you take a urine hCG test at home very early after conception, you may get a false negative result.

False positive result

A false positive result is when the test shows that you're pregnant, but you're not.

A urine hCG test may give a false positive result if you have a UTI or blood in your urine. Some medicines can also cause a false positive result.

If you suspect your home urine hCG test results are incorrect, it is important to get your results checked by your doctor with a blood test.

You can read more about hCG levels during your pregnancy on the Pregnancy, Birth and Baby website (Opens in new tab).

Visit the Pathology Tests Explained (Opens in new tab) website or Pregnancy, Birth and Baby (Opens in new tab) for more information about hCG tests.

Read our 'Guide to blood testing' to learn more about blood tests in general with information on:

• what to consider before having the test
• what happens during a blood test
• the accuracy of your results
• the costs of your blood tests

You can learn more in our article about urine tests.