Fetal alpha-fetoprotein (AFP) in maternal serum/plasma
This test measures the level of alpha-fetoprotein, a protein produced by the fetal liver and yolk sac, in your blood. It helps identify risks for certain birth defects or neural tube defects.
["AFP screening is a key part of prenatal care to check for potential health concerns in your baby."]
Key facts at a glance
- LOINC
- 11723-4
- Short code
- Fet Umb a fetus-plc Vmax sys DOP
- Synonyms
- Fet Umb a fetus-plc Vmax sys DOP
- 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-doppler
- 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 during your second trimester (around 15 to 20 weeks of pregnancy) as part of a general screening for neural tube defects (like spina bifida) or other fetal abnormalities. It can also be used in combination with other tests for additional risk assessment.
What Does the Test Measure?
Alpha-fetoprotein is a protein made by the fetus. High levels in your blood may suggest an increased risk of neural tube defects, such as spina bifida or anencephaly. Very low levels could indicate other conditions, like certain chromosomal abnormalities.
How Is the Test Performed?
A blood sample is taken from your arm. The sample is sent to a lab where it is analyzed to measure the AFP protein levels. Results are compared to standard ranges based on your pregnancy week.
What Are Common Results?
Results are typically reported as a percentage or risk score relative to other pregnant women at the same gestational age. A higher-than-expected AFP level may prompt further testing, such as an amniocentesis or ultrasound.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: AFP plays a critical role in prenatal screening. Elevated levels often signal an increased risk of neural tube defects, prompting additional diagnostic evaluations. Low levels may raise concerns about other genetic conditions, though this is less common. Always discuss results with your healthcare provider to understand the full implications for your pregnancy.
Short name
Maternal AFP screening
Frequently asked questions
What does an elevated AFP level mean?
What if my AFP level is lower than expected?
How often is this test repeated during pregnancy?
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