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Maternal Serum Alpha-Fetoprotein (AFP) with Other Related Markers (Screening for Neural Tube Defects and Other Fetal Conditions)

Published: August 9, 2026Updated: August 16, 2026

This blood test measures levels of alpha-fetoprotein and other markers in your maternal blood to help assess risks for certain fetal conditions, including neural tube defects.

Quick summary

["AFP screening helps identify potential birth defects early for further evaluation or monitoring."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
92016-5
Short code
Maternal preg risks Doc
Synonyms
Maternal preg risks Doc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
44
Ref high
147
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84075
SNOMED
27550007
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

What Is Alpha-Fetoprotein (AFP)?

Alpha-fetoprotein (AFP) is a protein produced mainly by the fetal liver and yolk sac. In maternal blood, elevated AFP levels can indicate conditions like neural tube defects (e.g., spina bifida) or other fetal abnormalities. This test may also include additional markers to provide a more comprehensive assessment.

Why Is This Test Done?

Your healthcare provider may recommend this test during pregnancy to screen for neural tube defects, chromosomal abnormalities, or other fetal issues. It’s often part of a first-trimester or second-trimester screening process.

When Is the Test Performed?

AFP screening is typically done between 15 and 22 weeks of pregnancy, though timing can vary based on clinical guidelines. Blood is drawn from a vein in your arm.

What Does the Test Involve?

A small amount of blood is collected from your arm using a needle. The sample is then sent to a lab for analysis. Results are usually available within a few days.

Reference range

Adult: 44-147 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

AFP Screening

Frequently asked questions

What does an abnormal AFP result mean?
An abnormal AFP result may indicate an increased risk for neural tube defects or other fetal anomalies. Your healthcare provider will discuss next steps, such as additional testing or monitoring, based on your specific results and pregnancy timeline.
Will I need to prepare for this test?
No special preparation is needed. You can eat and drink normally before the test, but avoid smoking or caffeine if advised by your provider.
Are there any risks or side effects?
The most common side effect is a slight bruise or minor discomfort at the needle insertion site. Rarely, there may be a reaction to the blood draw, such as dizziness or fainting. Your provider will monitor you during the procedure.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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 16, 2026. · Read our editorial policy