An estradiol test measures the amount of a hormone called estradiol in the blood. Estradiol is the most important form of estrogen found in the body. Most of it is made in and released from the ovaries, adrenal cortex, and the placenta, which forms during pregnancy to feed a developing baby.
Estradiol is responsible for the growth of the female uterus, Fallopian tubes, and vagina. It promotes breast development and the growth of the outer genitals. The hormone plays a role in the distribution of body fat in women and stops the process of growing taller.
How the test is performed
Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.
Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
How to prepare for the test
Consult your health care provider about the need to stop taking drugs that can affect test results, including:
- Estrogen therapy
- Birth control pills
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
This test is used to check the function of the ovaries, placenta, or adrenal glands. Your doctor may order this test if certain types of ovarian tumors are suspected, when there is delayed or abnormal development of male or female body characteristics, or the menstrual cycle is absent. A woman's level of estradiol can vary widely, depending on where she is in her menstrual cycle.
Women undergoing assisted reproductive technology (ART) for infertility may have this test at regular intervals in combination with ultrasound imaging to monitor their ovaries' response to stimulation.
- Male: 10 to 50 picograms per milliliter (pg/mL)
- Female (premenopausal): 30 to 400 pg/mL
- Female (postmenopausal): 0 to 30 pg/mL
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results mean
Greater-than-normal levels may indicate ovarian tumor.
Lower-than-normal levels may indicate Turner syndrome, ovarian failure, low estrogen production related to rapid weight loss or low body fat, and other conditions.
The test may also be used to monitor patients with hypopituitarism and women undergoing certain fertility treatments.
What the risks are
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Webster RA. Reproductive function and pregnancy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: Saunders Elsevier; 2006:chap 25.
Ferri FF. Laboratory tests and interpretation of results. In: Ferri FF, ed. Ferri’s Clinical Advisor 2009. 1st ed. Philadelphia, Pa: Mosby Elsevier; 2009:section IV.
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Redmond, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.