α-Fetoprotein (AFP), Maternal Serum for Open Spina Bifida
Also known as: AFP, Maternal Serum, Alpha-Fetoprotein (AFP), Maternal Serum for Open Spina Bifida, Maternal Serum α-Fetoprotein, msAFP
Use
Screening test for open neural tube defects. Detects 80% of open spina bifida and 90% of anencephaly. Please note that this test does not provide screening for Down syndrome or trisomy 18.
Special Instructions
The test requires detailed patient information including gestational age, date of gestational age determination, method of determination (LMP, EDD, US), patient's weight, date of birth, race (white, black, other), and insulin-dependent diabetic status. Accurate information is essential for interpreting results accurately. Specimens must be collected before amniocentesis to avoid contamination with fetal blood.
Limitations
This is a screening test and does not confirm the presence of neural tube defects. A positive result prompts additional diagnostic testing. It does not screen for Down syndrome or trisomy 18 and cannot detect closed neural tube defects.
Methodology
Immunoassay (CLIA)
Biomarkers
LOINC Codes
- 48802-3
- 31993-9
- 41274-2
- 18185-9
- 21299-3
- 43993-5
- 21484-1
- 29463-7
- 44877-9
- 45371-2
- 1834-1
- 20450-3
- 48803-1
- 49246-2
- 8251-1
- 8262-8
- 11502-2
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
3 mL
Minimum Volume
0.5 mL
Container
Gel-barrier tube
Collection Instructions
Collect in serum separator tube with gel barrier. Allow blood to clot, avoiding hemolysis. Separate serum from cells by centrifugation. Transport spun tube to testing laboratory. Pour-off is not advised. Maternal serum specimens must be drawn prior to amniocentesis to avoid contamination with fetal blood.
Storage Instructions
Room temperature
Causes for Rejection
Gross hemolysis; gross lipemia; quantity not sufficient for analysis; improper specimen type
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 14 days |