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17ohppredexserplmcnc

Published: August 9, 2026Updated: August 10, 2026

A blood test that measures 17-hydroxyprogesterone levels to help diagnose and monitor congenital adrenal hyperplasia (CAH), performed before dexamethasone administration.

Quick summary

{"Measures 17-OHP hormone levels in blood serum","Helps diagnose congenital adrenal hyperplasia (CAH)","Performed before dexamethasone dose to get baseline levels","Used to monitor treatment effectiveness in CAH patients","Sample is collected via blood draw"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 10, 2026Editorial policy

Key facts at a glance

LOINC
57545-6
Short code
17-OHP
Synonyms
17OHP Pre Dex SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red top serum separator tube (SST) or plain red top tube
Units
N/A
Ref low
0.2
Ref high
1
Critical range
— – 10 N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) or Chemiluminescent Immunoassay (CLIA)
CPT
83498
SNOMED
31316001
Specimen volume
1.0 mL minimum, 2.0 mL preferred
Stability
Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
Hemolysis max
50
Lipemia max
300
Icterus max
20
TAT
24–72 hours
Order
routine

What is this test?

The 17-Hydroxyprogesterone (17-OHP) test measures the amount of 17-hydroxyprogesterone in your blood. 17-OHP is a hormone produced by the adrenal glands that serves as a precursor to cortisol, the body's main stress hormone. This specific test is performed before giving dexamethasone medication to establish a baseline measurement of your natural hormone levels.

Why do I need this test?

This test is primarily used to screen for and diagnose congenital adrenal hyperplasia (CAH), a genetic disorder that affects the adrenal glands' ability to produce cortisol and aldosterone. It may also be used to monitor how well treatment is working in patients already diagnosed with CAH. The pre-dose dexamethasone timing helps your healthcare provider understand how your adrenal glands function under normal conditions before any medication effects.

How is the test performed?

A healthcare professional will draw a small blood sample from a vein in your arm. The blood will be collected in a tube and sent to a laboratory for analysis. The procedure is quick and typically takes only a few minutes. You may experience minor discomfort or bruising at the puncture site, but serious complications are rare.

Reference range

Reference range varies by age and sex. Adults: 0.2-1.0 ng/mL (0.6-3.0 nmol/L). Newborns (cord blood): 1.0-4.0 ng/mL. Preterm infants: May have higher ranges. Specific reference ranges should be established by the testing laboratory.N/A

Specimen: serum

This is a pre-dose dexamethasone sample. Collect blood before administering dexamethasone suppression test dose. No specific fasting required, but avoid strenuous exercise before sample collection. Inform laboratory of current medications, especially glucocorticoids or hormonal contraceptives.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Why is this test done before dexamethasone?
Measuring 17-OHP before administering dexamethasone allows your doctor to see your natural baseline hormone levels. Dexamethasone is a corticosteroid that suppresses adrenal hormone production, so testing afterward would not give an accurate picture of how your adrenal glands are functioning on their own.
What do high 17-OHP levels mean?
High 17-OHP levels usually suggest congenital adrenal hyperplasia (CAH). CAH is a genetic condition where the adrenal glands cannot produce enough cortisol, causing 17-OHP to build up. Your healthcare provider may recommend additional tests and consultation with an endocrinologist for proper diagnosis and management.
Do I need to fast before this test?
Follow your healthcare provider's specific instructions. Generally, no special preparation is needed for this test, but it's best to confirm with your doctor or the testing facility beforehand.
Is this test only for children?
No, this test is used for patients of all ages. It is commonly used in newborn screening programs to detect CAH early, but it is also performed in adults who show symptoms of the condition or are being monitored for CAH treatment.
  1. 1
    MedlinePlus - 17-HydroxyprogesteroneSource
  2. 2
    Mayo Clinic - Congenital Adrenal HyperplasiaSource
  3. 3
    National Institutes of Health - Congenital Adrenal HyperplasiaSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 10, 2026. · Read our editorial policy