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Acthamnriamcnc

Published: August 9, 2026Updated: August 17, 2026

This test measures the level of corticotropin (ACTH) in the amniotic fluid surrounding the baby during pregnancy.

Quick summary

{"ACTH is a hormone that helps regulate stress response and adrenal gland function","This test uses a radioimmunoassay (RIA) technique to measure hormone levels in amniotic fluid","It helps doctors assess fetal adrenal gland development and function","The test is performed on amniotic fluid collected during amniocentesis","Results can help identify certain fetal endocrine disorders"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
16652-0
Short code
ACTH Amn RIA-mCnc
Synonyms
ACTH Amn RIA-mCnc
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Ref low
10
Ref high
60
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ria
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

What is this test?

The Corticotropin (ACTH) in Amniotic Fluid test measures the amount of adrenocorticotropic hormone in the amniotic fluid. ACTH is produced by the pituitary gland and plays a crucial role in stimulating the adrenal glands to produce cortisol, which helps the body manage stress and maintain blood pressure and blood sugar levels. This test uses a specialized technique called radioimmunoassay (RIA) to detect and measure the hormone at very low levels.

How is the test performed?

During an amniocentesis procedure, a small sample of amniotic fluid is collected from the uterus using a thin needle guided by ultrasound. The fluid sample is then sent to a laboratory where it is analyzed using radioimmunoassay techniques to measure the ACTH concentration. This procedure is typically performed in the second trimester of pregnancy, usually between 15-20 weeks.

Why might I need this test?

Your healthcare provider may recommend this test if there are concerns about fetal adrenal gland development or function. It may be used to evaluate babies at risk for certain endocrine disorders, including congenital adrenal hyperplasia (CAH), or to assess fetal well-being in high-risk pregnancies. The test helps doctors understand how well the baby's endocrine system is developing.

Reference range

NCBI: ACTH 10-60 pg/mLN/A

Specimen: fluid

Typically collected in the morning (8-10 AM). Inform your provider if taking steroid medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is this test safe for my baby?
The test requires amniocentesis, which carries a small risk of complications such as infection, bleeding, or rarely, miscarriage. Your healthcare provider will discuss the risks and benefits with you. The procedure is performed under ultrasound guidance to minimize risks.
How long does it take to get results?
Results typically take several days to a week, as the test requires specialized laboratory techniques (radioimmunoassay) and may be sent to a reference laboratory.
What do abnormal results mean?
Abnormal ACTH levels in amniotic fluid may indicate potential fetal endocrine issues that require further investigation. Your healthcare provider will explain what the results mean for your specific situation and recommend any necessary follow-up testing or consultations with a specialist.
Will I need to fast before this test?
No fasting is required for this test. The test measures hormone levels in amniotic fluid, not in blood, so maternal fasting is not necessary.
  1. 1
    MedlinePlus - AmniocentesisSource
  2. 2
    Mayo Clinic Laboratories - ACTHSource

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 17, 2026. · Read our editorial policy