Additional Information:
UFHPL Epic order code: LAB4509
References
- Haddow JE, Palomaki GE, Knight GJ, Foster DL, Neveux LM. Second trimester screening for Down’s syndrome using maternal serum dimeric inhibin A. J Med Screen. 1998; 5(3):115-119. PubMed 9795869
CPT Code(s):
82105, 82677, 84702, 86336
Collection Procedure:
Avoid hemolysis. Submit the complete specimen in its original tube. Do not pour off.
Specimen Requirements:
Type: Serum
Container/Tube: Gel-barrier tube (no thrombin additive)
Sample Volume: 5 mL
Minimum Volume: 3 mL
Storage: Store specimens at room temperature after collection.
Stability (collection to time of analysis/testing):
- Ambient: 7 days
- Refrigerated: 14 days
- Frozen: 14 days
- Freeze/Thaw cycles: Stable (x3)
Rejection Criteria:
- Gross hemolysis
- Gross lipemia
- Quantity not sufficient for analysis (QNS samples)
Use:
This is a screening test for:
- Open neural tube defects (detects 80 percent of open spina bifida and 90 percent of anencephaly)
- Down syndrome (detects 75 to 80 percent)
- Trisomy 18 (detects 73 percent)
Limitations
A positive AFP tetra result means that more diagnostic testing may be offered to the patient to determine if a neural tube defect or chromosome abnormality is present.
Methodology:
Immunochemiluminometric assay (ICMA)