Test Overview
An estrogen test measures the level of the most
important estrogen
hormones (estradiol, estriol, and estrone) in a blood
or urine sample.
- Estradiol is the most commonly measured type of
estrogen for nonpregnant women. The amount of estradiol in a woman's blood
varies throughout her
menstrual cycle. After
menopause, estradiol production drops to a very low
but constant level.
- Estriol levels usually are only measured during
pregnancy. Estriol is produced in large amounts by the
placenta, the tissue that links the fetus to the
mother. It can be detected as early as the 9th week of pregnancy, and its
levels increase until delivery. Estriol can also be measured in
urine.
- Estrone may be measured in women who have gone through
menopause to determine 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 produce estrogen hormones. Estrogens are
responsible for female sexual development and function, such as breast
development and the menstrual cycle. In women, estrogens are produced mainly in
the ovaries and in the placenta during pregnancy. Small amounts are also
produced by the adrenal glands. In men, small amounts of estrogens are produced
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.
Generally done between 15 and 20 weeks, these tests 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 estimate
the chance that the baby may have certain problems or birth defects.
Why It Is Done
A test for estrogen is done to:
- Help detect fetal birth defects (especially
Down syndrome) during pregnancy. When the test for
estriol is combined 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.
- Evaluate estrogen-producing tumors of the ovaries
in girls before menstruation starts and in women after
menopause.
- Explain abnormal sexual characteristics in men, such as
enlarged breasts (gynecomastia). This test can also help detect the presence of
estrogen-producing tumors growing in the testicles.
- Monitor therapy
with fertility medicines.
How To Prepare
No special preparation is required
before having an estrogen test.
Tell your doctor if
you:
- Are menstruating. Note where you are in your
menstrual cycle.
- Are using birth control pills, patches, or rings and other forms
of hormonal birth control.
- Are or might be pregnant.
Talk to your doctor about any concerns you
have regarding 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 drawing 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.
- Apply a gauze pad or cotton ball over the needle site as
the needle is removed.
- Apply pressure to the site and then a
bandage.
How It Feels
You may feel nothing at all from the
needle puncture, or you may feel a brief sting or pinch as the needle goes
through the skin. Some people feel a stinging pain while the needle is in the
vein. But many people do not feel any pain or have only minor discomfort
after the needle is positioned in the vein.
Risks
There is very little risk of complications from
having blood drawn from a vein.
- You may develop a small bruise at the puncture
site. You can reduce the risk of bruising by keeping pressure on the site for
several minutes after the needle is withdrawn.
- In rare cases, the
vein may become inflamed after the blood sample is taken. This condition is
called phlebitis and is usually treated with a warm compress applied several
times daily.
- Continued bleeding can be a problem for people with
bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning
medicines can also make bleeding more likely. If you have bleeding or clotting
problems, or if you take blood-thinning medicine, tell your health professional
before your blood is drawn.
Results
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.
Normal
For girls and women between puberty and
menopause, estrogen levels vary throughout the
menstrual cycle.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Many conditions can change
estrogen levels. Your doctor will discuss any significant abnormal
results with you in relation to your symptoms and past health.
High values
High values may be caused by:
Low values
Low values may be caused by:
- Problems with ovarian function, which can be
caused by a failure of an ovary to develop properly (Turner's syndrome) or because of a drop in
pituitary gland activity.
- Anorexia nervosa.
- Menopause.
- A
problem with the fetus or placenta during pregnancy.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Hormone therapy after menopause.
- Birth control pills, patches, or
rings and other forms of hormonal birth control.
- Having a test that
uses a radioactive substance, such as a
bone scan, within 1 week before the
test.
- Medicines, such as clomiphene or steroids
(for example, prednisone).
- High levels of sugar in the urine caused
by
diabetes.
What To Think About
- Blood estrogen levels are a more accurate
indicator of how well the ovaries are working than urinary estrogen
levels.
- 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. For more
information, see the topics
Progesterone,
Luteinizing Hormone, and
Follicle-Stimulating Hormone.
- In some cases a
combination of screening tests is done in the first trimester to look for
Down syndrome. The first trimester screening often
combines ultrasound measurement of the thickness of the fetus's neck (nuchal
translucency) and measurements of hCG and a protein called pregnancy-associated
plasma protein A to check for problems. For more information, 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. For more information, see the topic Triple or Quad Screening for Birth Defects.
References
Citations
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis:
Saunders.
- Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
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.
Credits
| By | Healthwise Staff |
|---|
| Primary Medical Reviewer | Sarah Marshall, MD - Family Medicine |
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| Specialist Medical Reviewer | Siobhan M. Dolan, MD, MPH - Reproductive Genetics |
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| Last Revised | April 4, 2012 |
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Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis:
Saunders.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.