- Estradiol is the most common type of estrogen measured for nonpregnant women. The amount of estradiol in a woman's blood varies throughout her menstrual cycle. After menopause, it drops to a very low but constant level.
- Estriol levels are most often measured only during pregnancy. Estriol is produced in large amounts by the placenta. This is the tissue that links the fetus to the mother. Estriol can be found as early as the 9th week of pregnancy. The levels keep rising until delivery. Estriol can also be measured in urine.
- Estrone may be measured in women who have gone through menopause. It's done to find out their estrogen levels. It also may be measured in men or women who might have cancer of the ovaries , testicles , or adrenal glands .
Both men and women make estrogen hormones. Estrogens are responsible for female sexual development and function, such as breast development and the menstrual cycle. In women, estrogens are made mainly in the ovaries and in the placenta during pregnancy. Small amounts are also made by the adrenal glands. In men, small amounts of estrogens are made by the adrenal glands and testicles.
Small amounts of estrone are made throughout the body in most tissues, especially fat and muscle. This is the major source of estrogen in women who have gone through menopause.
For pregnant women, the level of estriol in the blood is used in a maternal serum triple or quadruple screening test. In most cases, these tests are done between 15 and 20 weeks of pregnancy. They check the levels of three or four substances in a pregnant woman's blood. The triple screen checks alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and a type of estrogen (unconjugated estriol, or uE3). The quad screen checks these substances and the level of the hormone inhibin A. The levels of these substances-along with a woman's age and other factors-help the doctor figure out the chance that the baby may have certain problems or birth defects.
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Why It Is Done
A test for estrogen is done to:
- Help find fetal birth defects (especially Down syndrome) during pregnancy. When the test for estriol is done with alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG), it is called a triple screen test. When the amount of a hormone called inhibin A is also measured along with estriol, AFP, and hCG, the test is called a quad marker screen. Other blood tests and fetal ultrasound may be done as well.
- Check for estrogen-producing tumors of the ovaries in girls before menstruation starts and in women after menopause.
- Explain abnormal sexual traits in men, such as enlarged breasts (gynecomastia). This test can also help find out if there are estrogen-producing tumors growing in the testicles.
- Monitor treatment with fertility medicines.
How To Prepare
You do not need to do anything special to prepare for this test.
Tell your doctor if you:
- Are menstruating. Note where you are in your menstrual cycle.
- Are using birth control pills, patches, rings, or other forms of hormonal birth control.
- Are or might be pregnant.
Talk to your doctor if you have any concerns about the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
The health professional taking a sample of your blood will:
- Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
- Clean the needle site with alcohol.
- Put the needle into the vein. More than one needle stick may be needed.
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is collected.
- Put a gauze pad or cotton ball over the needle site as the needle is removed.
- Put pressure on the site and then put on a bandage.
How It Feels
You may feel nothing at all from the needle, or you may feel a quick sting or pinch. Some people feel a stinging pain while the needle is in the vein. But many people feel little or no pain after the needle is in the vein.
There is very little chance of a problem from having a blood sample taken from a vein.
- You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
- In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. You can use a warm compress several times a day to treat this.
- Bleeding can be a problem for people who have bleeding disorders or take blood-thinning medicines such as aspirin or warfarin (Coumadin). If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your doctor before your blood sample is taken.
An estrogen test measures the level of the most important estrogen hormones (estradiol, estriol, and estrone) in a blood or urine sample.
Results are usually available within 24 hours.
For girls and women between puberty and menopause, estrogen levels vary throughout the menstrual cycle.
These numbers are just a guide. The range for "normal" varies from lab to lab. Your lab may have a different range. Your lab report should show what range your lab uses for "normal." Also, your doctor will evaluate your results based on your health and other factors. So a number that is outside the normal range here may still be normal for you.
Women before menopause:
Women after menopause:
Less than 130 pg/mL
Less than 25 pg/mL
Less than 38 nanograms per milliliter (ng/mL)
Many conditions can change estrogen levels. Your doctor will talk with you about any important abnormal results as they relate to your symptoms and past health.
High values may be caused by:
- Ovarian stimulation used to treat infertility (for example, before in vitro fertilization).
- Cancer, such as cancer of the ovaries , testicles , or adrenal glands .
- Serious liver disease (cirrhosis).
- A pregnancy with more than one fetus, such as twins or triplets.
- Early puberty.
Low values may be caused by:
What Affects the Test
You may not be able to have the test, or the results may not be helpful, if:
- You use hormone therapy after menopause.
- You use birth control pills, patches, or rings and other forms of hormonal birth control.
- Within 1 week before your test, you had a test that uses a radioactive substance, such as a bone scan.
- You use certain medicines, such as clomiphene or steroids (for example, prednisone).
- You have high levels of sugar in your urine caused by diabetes.
What To Think About
- A blood test works better than a urine test to see how well the ovaries are working.
- Tests that measure blood levels of progesterone, luteinizing hormone, and follicle-stimulating hormone are often used to study the problems that can affect fertility and the menstrual cycle.
- In some cases, screening tests are done in the first trimester of pregnancy to look for Down syndrome. The first trimester screening is often an ultrasound that measures the thickness of skin at the back of the fetus's neck (nuchal translucency). It also includes a blood test for the pregnancy hormone hCG and a protein called pregnancy-associated plasma protein A. To learn more, see the topic Birth Defects Testing.
- The level of estriol in the blood is often used in a maternal serum triple or quadruple screening test. To learn more, see the topic Triple or Quad Screening for Birth Defects.
Other Works Consulted
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
Wapner RJ, et al. (2009). Prenatal diagnosis of congenital disorders. In RK Creasy et al., eds., Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice, 6th ed., pp. 221-274. Philadelphia: Saunders Elsevier.
Primary Medical ReviewerSarah Marshall, MD - Family Medicine
Specialist Medical ReviewerSiobhan M. Dolan, MD, MPH - Reproductive Genetics
Current as ofFebruary 20, 2015