17-Hydroxyprogesterone (17-OHP) Test
Reviewed
This test measures the amount of 17-hydroxyprogesterone (17-OHP) in your blood. 17-OHP is a substance made by the adrenal glands. The test is used to help diagnose and monitor congenital adrenal hyperplasia (CAH), most commonly due to 21-hydroxylase deficiency. It is part of routine newborn screening for severe CAH and may also be used in children, teens, and adults with symptoms of mild CAH. Results are not diagnostic by themselves and must be interpreted by your clinician along with other tests and your medical history.
Preparation and collection
No special preparation is needed.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- This test is not diagnostic by itself; results must be interpreted by a clinician along with other tests and clinical findings.
- Newborn screening is most accurate when done more than 24 hours after birth; if tested sooner, a repeat test may be needed.
- Newborn screening cannot detect mild (nonclassic) CAH.
What to do next
If results are unclear, your provider may order an ACTH stimulation test, which measures 17-OHP and cortisol levels before and after an ACTH injection.
Evidence source
U.S. National Library of Medicine: 17-Hydroxyprogesterone (17-OHP) Test