What is an oestrogen blood test?

Oestrogen (also known as estrogen) is a sex hormone. It's produced by both females and males, although in much greater amounts in females.

Oestrogen helps the female reproductive organs — the ovaries, fallopian tubes, uterus (womb) and vagina — to grow and mature. It also helps with breast development.

Oestrogen levels rise naturally during puberty and fall after menopause.

Many females will have a blood test for oestrogen at some point in their lives. This might be during puberty, pregnancy or if you are having difficulty getting pregnant.

A blood test can check the levels of 3 types of oestrogen:

• oestradiol — important for ovulation (release of eggs) and becoming pregnant, and also supports healthy bones and cholesterol levels in females
• oestriol — important during pregnancy; oestriol levels usually start to rise after week 8 of pregnancy
• oestrone — the most important oestrogen after menopause

When is an oestrogen blood test used?

Your doctor might suggest an oestrogen blood test if:

• your menstrual cycle isn't regular, or you have heavy bleeding
• you are having difficulty becoming pregnant
• you have symptoms of menopause, such as hot flushes
• you have symptoms of a hormonal condition

An oestrogen blood test can help diagnose perimenopause or menopause.

If you are pregnant, you might have a blood test to check your oestriol levels:

• as part of screening for Down syndrome in your unborn child
• to check that your placenta is working properly

Young people may have an oestrogen blood test if there is concern about their sexual development, for example, starting their periods (menstruation) much earlier than expected.

Your doctor may also request an oestrogen blood test if you are being treated with hormone replacement therapy.

Oestrogen blood tests can help detect tumours that release hormones such as oestrogen.

Where can I get an oestrogen blood test?

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

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

How do I prepare for an oestrogen blood test?

There are no special preparations needed for an oestrogen blood test.

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.

What happens during an oestrogen blood test?

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.

What do my oestrogen blood test results mean?

Oestrogen levels naturally vary during your lifetime, particularly during pregnancy and as you age. The levels of each type of oestrogen in your blood can change every day, and your oestradiol levels vary during different phases of your menstrual cycle.

A result outside the normal range might not mean you have a health problem. You may need several tests over weeks or months to monitor your oestrogen levels and investigate any changes.

Your doctor is the best person to talk to about your blood test results. You can ask them what they mean and what comes next.

Resources and support

To learn more about blood tests, you can read healthdirect's Guide to blood testing.

Pathology Tests Explained also has lots of information on blood tests, including oestrogen tests.

For more information on blood tests during pregnancy check out Pregnancy Birth and Baby.