17-OH progesterone

Alternative names 
17-hydroxyprogesterone; Progesterone - 17-OH

This is a blood test that measures the amount of 17-OH progesterone.

How the test is performed

Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to cause the vein below the band to swell with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

For an infant or young child, the area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

After the blood has been drawn, it is sent to a laboratory to be evaluated.

How to prepare for the test
The health care provider will instruct you, if necessary, to discontinue drugs that may interfere with the test. These include corticosteroids and birth control pills. The health care provider may advise that the test be performed at a specific time of day, because this can affect the test results.

Fo infants and children:
The preparation you can provide for this test depends on your child’s age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following:

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 some throbbing.

Why the test is performed
This test is used primarily to identify patients with congenital adrenal hyperplasia (CAH). CAH is a rare genetic disorder that results from a deficiency of a particular enzyme that normally makes cortisol in the adrenal gland. This deficiency results in abnormal levels of certain steroids and hormones, specifically increasing androgens (male hormones) and decreasing glucocorticoids.

Normal Values


  • 3 to 32 ng/dL


  • day 1 to 14 of menstrual cycle: 15 to 70 ng/dL  
  • day 15 to end of menstrual cycle: 35 to 290 ng/dL

Note: ng/dL = nanograms per deciliter

What abnormal results mean
Levels higher than 200 ng/dL may indicate CAH.

What the risks are

  • excessive bleeding  
  • fainting or feeling lightheaded  
  • hematoma (blood accumulating under the skin)  
  • infection (a slight risk any time the skin is broken)  
  • multiple punctures to locate veins

Special considerations
This test is sensitive to circadian rhythms (the natural peaks and lows that the body experiences during a day).

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.

Johns Hopkins patient information

Last revised: December 7, 2012
by Sharon M. Smith, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.