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Print CPT [MAAA: 81511] or 82105; 82677; 84702; 86336
Synonyms
- AFP, Maternal
- Down Syndrome
Test Details
Turnaround Time
2 - 5 days
Use
Screening test for open neural tube defects, Down syndrome, and trisomy 18
Special Instructions
For test inquiries, call CMBP genetic services at 800-345-4363. Patient must have submitted a previous specimen in the first trimester for the Sequential 1 test. Gestational age will be based on crown rump length provided with the first trimester specimen. Patient information may be provided to the laboratory using the Maternal Prenatal Screening test request form 0900. Testing is provided from 15.0 to 21.9 weeks of gestation.
Limitations
Sequential screening requires two specimens: one collected in the first trimester and one in the second trimester. This test number is for the second trimester portion of the test. This is a screening test. A positive result means that diagnostic testing may be offered to the pregnant woman to determine if a neural tube defect or chromosome abnormality is present.
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Methodology
Chemiluminescent immunoassay
Specimen Requirements
Information on collection, storage, and volume
Specimen
Whole blood; serum
Volume
Serum: 2-3 mL (unhemolyzed). Whole Blood: 7 mL in SST or 10 ml in red-top tube; allow to clot; centrifuge (15 minutes at 1,000 g) to prevent hemolysis.
Minimum Volume
3 mL
Container
Serum: AFP tube Whole Blood: Serum separator tube (SST) or red-top tube.
Storage Instructions
Maintain at room temperature
Causes for Rejection
Gross hemolysis; gross lipemia; quantity not sufficient for analysis
Collection
Avoid hemolysis. Send complete specimen in the original tube. Do not pour off.