Lab Test

Alpha Fetoprotein, Amniotic Fluid

Amniotic Fluid-AFP, Alphafetoprotein- Amniotic Fluid, Alphafetoprotein, Amniotic Fluid

Test Codes



Special Chemistry


An "Amniotic Fluid AFP" requisition form should be sent with each sample. This must include the following information:

  • Reason for amniocentesis.
  • Ultrasound information on gestational age.

Specimen Collection Criteria

Collect: 2.0 mL amniotic fluid in a sterile collection container. (Minimum: 1.5 mL)

Physician Office/Draw Specimen Preparation

Refrigerate (2-8°C or 36-46°F) specimen after collection and arrange for transportation to the Laboratory immediately. Room temperature is acceptable for a maximum of 4 hours. (Minimum: 1.5 mL)

Preparation for Courier Transport

Transport: 2.0 mL amniotic fluid, refrigerated (2-8°C or 36-46°F). (Minimum: 1.5 mL)

Rejection Criteria

Specimens not collected and processed as indicated.

Inpatient Specimen Preparation

Send specimen to the Laboratory for processing immediately after collection. (Minimum: 1.5 mL)

In-Lab Processing

Refrigerate specimen prior to testing. Room temperature is acceptable for a maximum of four hours. (Minimum: 1.5 mL)


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 4 hours
Refrigerated (2-8°C or 36-46°F): 4 months
Frozen (-20°C/-4°F or below): 3 years

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days


Royal Oak Special Testing Laboratory
Samples with an abnormal result or abnormal history will be automatically sent to Mayo in Minnesota.


Monday – Friday.
Results available within 2 business days.

Reference Range

The AFP result is reported as a MoM (multiple of the median) - this is calculated for the appropriate gestational age. When the MoM is greater than 1.5 an abnormality may be present. Such a sample needs additional testing (repeat AFP and acetylcholinesterase). Repeat testing is sent to Mayo (test code:ACHE).

Test Methodology

Chemiluminescent immunoassay.
ARUP uses Qualitative Gel Electrophoresis/Radial Immunodiffusion.


By report.

Clinical Utility

This assay aids in evaluating a patient's pregnancy for neural tube defects. The assay may be ordered if a patient has an elevated serum AFP or an abnormal ultrasound. It may be appropriate in patients with insulin-dependent diabetes mellitus or those taking valproic acid.

CPT Codes

LOINC: 1832-5


Last Updated


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