Alpha Fetoprotein (Amniotic Fluid) with Reflex to Acetylcholinesterase and Fetal Hemoglobin
Also known as: AF AFP
Use
This test is used to evaluate the possibility of a fetal open neural tube defect in pregnant women between 13 to 36 weeks of gestation. Alpha-fetoprotein (AFP) measurement in amniotic fluid can help identify pregnancies at increased risk for fetal abnormalities, including neural tube defects such as spina bifida. Early detection allows for informed clinical management and options for further diagnostic investigations, such as high-resolution ultrasound or genetic testing.
Special Instructions
Submit with order the gestational age at time of amniotic fluid collection or estimated due date. The test relies on precise gestational age to ensure accurate interpretation of AFP levels. If AFP levels are elevated, reflex testing for acetylcholinesterase and fetal hemoglobin is performed, which requires an additional 3-11 days for reporting.
Limitations
The test is not FDA-cleared or approved, although it is performed in a CLIA-certified laboratory. Results require careful interpretation in the context of the clinical picture and other diagnostic evaluations. Elevated AFP can indicate neural tube defects but can also be seen with other conditions such as abdominal wall defects or incorrect gestational dating. Normal results do not exclude all fetal developmental issues.
New York Approved
Methodology
Immunoassay (CLIA)
Biomarkers
LOINC Codes
- 1832-5
- 29595-6
- 41273-4
- 18185-9
Result Turnaround Time
3-4 days
Related Documents
For more information, please review the documents below
Specimen
Amniotic Fluid
Volume
2.5 mL
Minimum Volume
1.5 mL
Collection Instructions
Amniocentesis should be performed, and amniotic fluid must be drawn between 13 weeks, 0 days and 36 weeks, 6 days gestation.
Patient Preparation
The specimen should be collected through amniocentesis within the specified gestation period.
Storage Instructions
Transport at room temperature.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 month |
| Refrigerated | 3 months |
| Frozen | 3 months |