Chromosome Analysis, AFP, AChE, Amniotic Fluid With Reflex to Fetal Hemoglobin (Hb F)
Use
Determine fetal karyotype; prenatal diagnosis of Down syndrome or other chromosomal abnormalities; analysis of midtrimester amniotic fluid for detection of open neural tube and ventral wall defects
Special Instructions
State gestational age (in weeks) on the day the sample was drawn on the test request form. The patient's gestational age must be between 12 weeks and 24 weeks for interpretation of AF-AFP, as AChE false-positive and false-negative results occur more frequently at gestational ages less than 13 weeks or greater than 24.9 weeks. If prior NIPT studies have been performed, include a copy of the report.
Limitations
The performance characteristics of this test were developed and determined by Labcorp. However, the test has not been cleared or approved by the Food and Drug Administration. As the test interpretation depends on gestational age, precise gestational dating is critical for accurate results. Additionally, the presence of blood contamination in the amniotic fluid can result in false elevations of AFP.
Methodology
Chromosomal / Cytogenetics (Karyotype)
Biomarkers
LOINC Codes
- 64095-3
- 64096-1
- 64092-0
- 64091-2
- 64093-8
- 62356-1
- 62357-9
- 48002-0
- 48672-0
- 11502-2
- 1832-5
- 29253-2
- 49051-6
- 41273-4
- 72486-4
- 30106-9
- 76479-5
- 28067-7
Result Turnaround Time
9-12 days
Related Documents
For more information, please review the documents below
Specimen
Amniotic Fluid
Volume
20 to 30 mL
Minimum Volume
10 mL
Container
Sterile plastic conical tube; do not use urine containers or tubes with rubber stoppers.
Collection Instructions
Discard first 2 mL of fluid to avoid maternal cell contamination. Specimen should be collected in a 20 mL sterile syringe and transferred to sterile tubes for transport. Ensure the test request form accompanies the specimen.
Storage Instructions
Maintain specimen at room temperature. Do not freeze or refrigerate.
Causes for Rejection
Suitability of the specimen will be determined by the Cytogenetics laboratory upon receipt. Frozen specimens and those in contact with rubber stoppers will be rejected.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 month |
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