Fetoprotein (Alpha-Fetoprotein) in Amniotic Fluid
This test measures the level of alpha-fetoprotein (AFP), a protein produced by the fetus, in amniotic fluid collected during pregnancy. It helps assess fetal development and screen for certain birth defects.
["AFP in amniotic fluid helps detect potential genetic or structural birth defects early in pregnancy."]
Key facts at a glance
- LOINC
- 11782-0
- Short code
- Fet Bowel Diam US.meas
- Synonyms
- Fet Bowel Diam US.meas
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- us-measured
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may recommend this test if you’re at higher risk for certain birth defects, such as neural tube defects (e.g., spina bifida) or Down syndrome. It’s often part of a routine screening during the first trimester or second trimester of pregnancy.
What Does the Test Involve?
A small amount of amniotic fluid is collected through a procedure called an amniocentesis. A needle is inserted into the uterus under ultrasound guidance, and fluid is carefully removed for testing. This is usually done between 15 and 20 weeks of pregnancy.
What Are the Possible Results?
Results are interpreted in the context of your pregnancy timeline and other risk factors. Elevated AFP levels may indicate an increased risk of certain birth defects, while very low levels could suggest other conditions. Your healthcare provider will discuss findings with you.
What Are the Risks?
While rare, amniocentesis carries a small risk of complications, such as infection, bleeding, or preterm labor. Your provider will explain these risks before the procedure.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: AFP in amniotic fluid is primarily used as a screening tool to identify potential issues that may require further diagnostic testing. High or low AFP levels can signal conditions that warrant additional evaluation, such as chromosomal abnormalities or neural tube defects, though it is not a definitive diagnostic test alone.
Short name
AFP Amniotic Fluid
Frequently asked questions
What does an abnormal AFP level mean?
Is this test painful?
How soon will I get my results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy