Summary

• Beta hCG is a hormone produced by the placenta during pregnancy.
• Over-the-counter pregnancy tests work by detecting beta hCG in a sample of urine to confirm a pregnancy.
• Beta hCG can also be measured in a sample of blood to confirm a pregnancy and monitor its progress.
• This test is used to determine how far along a pregnancy is (gestational age of the baby).
• It can help make sure the pregnancy is developing normally. It can be used to help in investigating certain pregnancy-related complications such as ectopic pregnancy or miscarriage.
• Beta hCG is also used to diagnose and monitor certain cancers such as ovarian and testicular cancer and gestational trophoblastic disease.

What is beta Human Chorionic Gonadotrophin (beta hCG)?

Beta hCG is a hormone produced by the placenta during pregnancy. Beta HCG can first be found in your blood and urine at about 10 to 11 days after conception (the point when a sperm fertilises an egg). Your beta hCG levels are the highest towards the end of your first trimester (10 weeks of pregnancy), then become lower for the rest of your pregnancy.

Hormones are chemical messengers that are made by your glands. They travel in your bloodstream to control the actions of specific cells in your tissues or organs. When they reach their target, they attach to a cell’s receptors, stimulating a response.

As a hormone, beta hCG stimulates your body to create more hormones, including oestrogen and progesterone. Together they thicken the lining of your uterus to make it ready for the baby and tell your body to stop menstruating. The correct balance of these three hormones is important in sustaining the pregnancy. Beta hCG is no longer detectable a few weeks after the baby is born.

Why get tested?

Over-the-counter pregnancy tests

Detection of beta hCG in urine is the basis of the pregnancy test kits that are available over the counter in pharmacies and supermarkets. This is called a qualitative test, meaning it shows whether beta HCG is present or absent in your urine. It takes about two weeks for your beta hCG levels to be high enough to be detected by one of these kits.

A positive test result is almost always correct, but it is possible to have a negative result yet be pregnant. This can happen if you test too early or if your urine sample is very dilute because you have drunk a lot of fluid before the test. Some tests can detect lower levels of beta hCG than others.

Laboratory tests for monitoring a pregnancy

Testing can also measure the actual amount of beta hCG in blood. This is called a quantitative test, and it is performed in a laboratory. This test is used in assessing the progress of your pregnancy and investigate any complications that may arise. Serial hCG testing is commonly used to assess pregnancy viability, particularly in early pregnancy.

For most people, once they know they are pregnant, there will be no need to test for beta hCG again as the pregnancy proceeds to normal delivery. However, if something goes wrong with the pregnancy, the level of hCG can become higher or lower than expected.

Beta hCG levels may be lower than normal if you have an ectopic pregnancy. An ectopic pregnancy is when the fertilised egg implants somewhere other than in the uterus, often in a fallopian tube. This is a serious condition needing immediate treatment. The symptoms of an ectopic pregnancy are abdominal pain and uterine bleeding. If you have an ectopic pregnancy, you will still have a positive pregnancy test because your placenta still produces a small amount of beta hCG.

If you have a miscarriage the level of beta hCG will fall quickly.

Cancer testing

Beta hCG testing is used in diagnosing and monitoring two types of cancer.

Gestational trophoblastic disease

Beta hCG is released by certain types of tumours which develop from the placenta. This is called gestational trophoblastic disease (GTD). Most GTD tumours are benign, but some forms can become malignant (turn into cancer). However, even in its malignant forms, GTD has a high chance of successful treatment.

Germ cell cancers such as ovarian and testicular cancers.

Germ cells are the cells that develop into sperm or eggs. Germ cell cancers can develop in the ovaries or testicles, and less often, they develop in other parts of the body. They can occur at any age, but they are more common in children and young adults. When these tumours develop, the blood level of beta hCG increases significantly.

Blood tests for beta hCG are also needed to monitor these tumours, to check whether the treatment is effective.

Having the test

Sample

Blood

Any preparation?

None

Your results

Reading your report

Reference Intervals

Your results will be compared to reference intervals (sometimes called a normal range).

• Reference intervals are the range of results expected in healthy people
• When compared against them your results may be flagged high or low if they sit outside the range.
• Reference ranges may vary between different age groups.
• Reference intervals may vary between labs so only those results that are standardised or harmonised across most laboratories are given on this website.

If your results are flagged as high or low this does not necessarily mean that anything is wrong. Your doctor needs to take your medical history to help interpret your result.

Pregnancy

• If you are not pregnant, beta hCG levels in the blood are normally very low or undetectable. The reference interval for beta hCG in non-pregnant women is less than 5 IU/L. But it can be mildly elevated at up to 14 IU/L in some peri- and post-menopausal women.
• During early pregnancy, the beta hCG level in the blood doubles about every two to three days.
• If something is going wrong with the pregnancy, the beta hCG does not rise as expected and may even fall.
• Falling beta hCG levels can indicate a pregnancy loss (miscarriage).
• If you have a miscarriage, the beta hCG level in the blood falls rapidly. If it does not, it may indicate that there is remaining beta hCG-producing tissue that will need to be removed.
• Beta hCG levels that are rising more slowly than expected may be due to an ectopic pregnancy, or you may be at risk of having a miscarriage.
• If you are pregnant with twins or triplets you can expect to have higher levels of beta hCG.
• Levels of beta hCG in your blood cannot provide a diagnosis on their own. They can only indicate that further investigation is needed.

Diagnosis and monitoring of cancer

During cancer treatment, a falling beta hCG level generally indicates that a tumour is responding to treatment, while rising levels may indicate that a tumour is not responding. Increased beta hCG levels after treatment may indicate a recurrence of tumour.

False positive test results

The beta hCG test result can occasionally be falsely positive. This can happen because of conditions like ovarian cysts, kidney disease, or some cancers. It is also possible to get a false-positive result if your body produces certain types of antibodies. Some medications, including those used in fertility treatments, can also interfere with beta hCG levels.

Males

Reference interval for males is less than 5 IU/L.

Any more to know?

There are several forms of beta hCG. One type of beta hCG is tested as part of the pregnancy screening tests done to check for the risk of certain conditions in the unborn baby such as Down syndrome. This type of beta HCG is not the same as the beta hCG test used for detection of pregnancy or cancer.

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell them everything you think might help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods, medications or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

More information

Pathology and diagnostic imaging reports can be added to your My Health Record. You and your healthcare provider can now access your results whenever and wherever needed.

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