17-OH progesterone is a blood test that measures the amount of 17-OH progesterone. This is a hormone produced by the adrenal glands and sex glands.
17-hydroxyprogesterone; Progesterone - 17-OH
How the Test is Performed
A blood sample is needed. Most of the time blood is drawn from a vein located on the inside of the elbow or the back of the hand.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin.
The blood collects in a small glass tube called a pipette, or onto a slide or test strip.
A bandage is put over the spot to stop any bleeding.
How to Prepare for the Test
Many medicines can interfere with blood test results.
Your health care provider will tell you if you need to stop taking any medicines before you have this test.
Do not stop or change your medications without talking to your doctor first.
How the Test will Feel
You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.
Why the Test is Performed
The main use of this test is to check infants for an inherited disorder that affects the adrenal gland, called congenital adrenal hyperplasia (CAH). It is often done on infants who are born with outer genitals that do not clearly look like those of a boy or a girl.
This test is also used to identify people who have a condition called nonclassical adrenal hyperplasia. A doctor may recommend this test for women or girls who have male traits such as:
Excess hair growth in places where adult men grow hair
Deep voice or an increase in muscle mass.
Normal and abnormal values differ for babies born with low birth weight. In general, normal results are as follows:
Newborn cord blood - 1,000 - 3,000 ng/dL
Babies more than 24 hours old - less than 100 ng/dL
Adults - less than 200 ng/dL
Note: ng/dL = nanograms per deciliter.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
In infants with CAH, 17-OHP levels range from 2,000 - 40,000 ng/dL. In adults, a level greater than 200ng/dL may be due to nonclassical adrenal hyperplasia.
Your doctor may suggest an ACTH test if 17-OH progesterone level is between 200 - 800 ng/dL.
Fritz MA, Speroff L. Normal and abnormal sexual development. In: Speroff L, Fritz MA, eds. Clinical Gynecologic Endocrinology and Infertility. 8th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2011:chap 9.
Lambert SM, Vilain EJ, Kolon TF. A practical approach to ambiguous genitalia in the newborn period. Urol Clin North Am. 2010; 37(2):195-205.
Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.