Test Details
Methodology
Chemiluminescent immunoassay
Result Turnaround Time
2 - 5 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
Measurement of amniotic fluid AFP. Samples with AFP values ≥2.0 MoM will reflex to detection of acetylcholinesterase and fetal hemoglobin.
Use
Analysis of midtrimester amniotic fluid for detection of open neural tube defects and ventral wall defects
Special Instructions
Include the gestational age by ultrasound and/or last menstrual period (LMP) on the request form on the date of draw of the sample. The patient's gestational age must be between 12 weeks and 24 weeks for interpretation of α-fetoprotein. Note that AChE false-positive and false-negative results are more frequent at gestational ages less than 13 weeks or greater than 24.9 weeks. Optimal gestational age is 14 to 18 weeks.
Limitations
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Specimen Requirements
Specimen
Amniotic fluid
Volume
1 mL
Container
Sterile plastic conical tube; do not use urine containers or tubes with rubber stoppers. Rubber is toxic to amniocytes.
Collection Instructions
Avoid contamination of amniotic fluid with maternal or fetal blood. As little as one drop of fetal blood can cause false-positive results during assay of amniotic fluid. Amniotic fluid should be collected by the attending physician.
Storage Instructions
Ship and maintain specimen at room temperature.
Patient Preparation
The patient should have undergone ultrasound studies to verify fetal viability, detect multiple gestation, confirm gestational age, localize placenta, and detect fetal and uterine pathology.
Causes for Rejection
Specimen not amniotic fluid; gross contamination of amniotic fluid with maternal or fetal blood; quantity not sufficient for analysis
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 002428 | AFP, Amniotic Fluid | 58735-2 | 010806 | AFP, Amniotic Fluid | N/A | |
| 002428 | AFP, Amniotic Fluid | 58735-2 | 101352 | AFP Value | ug/mL | 1832-5 |
| 002428 | AFP, Amniotic Fluid | 58735-2 | 101360 | AFP MoM | 29253-2 | |
| 002428 | AFP, Amniotic Fluid | 58735-2 | 101379 | Gestational Age(Wks) | 49051-6 | |
| 002428 | AFP, Amniotic Fluid | 58735-2 | 101378 | Interpretation | 41273-4 | |
| 002428 | AFP, Amniotic Fluid | 58735-2 | 101376 | Director | 72486-4 | |
| 002428 | AFP, Amniotic Fluid | 58735-2 | 999500 | Amniotic Fluid, AFP | N/A | |
| Order Code | 002428 | |||||
| Order Code Name | AFP, Amniotic Fluid | |||||
| Order Loinc | 58735-2 | |||||
| Result Code | 010806 | |||||
| Result Code Name | AFP, Amniotic Fluid | |||||
| UofM | ||||||
| Result LOINC | N/A | |||||
| Order Code | 002428 | |||||
| Order Code Name | AFP, Amniotic Fluid | |||||
| Order Loinc | 58735-2 | |||||
| Result Code | 101352 | |||||
| Result Code Name | AFP Value | |||||
| UofM | ug/mL | |||||
| Result LOINC | 1832-5 | |||||
| Order Code | 002428 | |||||
| Order Code Name | AFP, Amniotic Fluid | |||||
| Order Loinc | 58735-2 | |||||
| Result Code | 101360 | |||||
| Result Code Name | AFP MoM | |||||
| UofM | ||||||
| Result LOINC | 29253-2 | |||||
| Order Code | 002428 | |||||
| Order Code Name | AFP, Amniotic Fluid | |||||
| Order Loinc | 58735-2 | |||||
| Result Code | 101379 | |||||
| Result Code Name | Gestational Age(Wks) | |||||
| UofM | ||||||
| Result LOINC | 49051-6 | |||||
| Order Code | 002428 | |||||
| Order Code Name | AFP, Amniotic Fluid | |||||
| Order Loinc | 58735-2 | |||||
| Result Code | 101378 | |||||
| Result Code Name | Interpretation | |||||
| UofM | ||||||
| Result LOINC | 41273-4 | |||||
| Order Code | 002428 | |||||
| Order Code Name | AFP, Amniotic Fluid | |||||
| Order Loinc | 58735-2 | |||||
| Result Code | 101376 | |||||
| Result Code Name | Director | |||||
| UofM | ||||||
| Result LOINC | 72486-4 | |||||
| Order Code | 002428 | |||||
| Order Code Name | AFP, Amniotic Fluid | |||||
| Order Loinc | 58735-2 | |||||
| Result Code | 999500 | |||||
| Result Code Name | Amniotic Fluid, AFP | |||||
| UofM | ||||||
| Result LOINC | N/A |
| Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
|---|---|---|---|---|---|---|
| Reflex 1 | 510206 | AChE+Hb F | 510172 | Acetylcholinesterase | 30106-9 | |
| Reflex 1 | ||||||
| Order Code | 510206 | |||||
| Order Name | AChE+Hb F | |||||
| Result Code | 510172 | |||||
| Result Name | Acetylcholinesterase | |||||
| UofM | ||||||
| Result LOINC | 30106-9 | |||||
| Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
|---|---|---|---|---|---|---|
| Reflex 1 | 510206 | AChE+Hb F | 510180 | Fetal Hemoglobin | 28067-7 | |
| Reflex 1 | ||||||
| Order Code | 510206 | |||||
| Order Name | AChE+Hb F | |||||
| Result Code | 510180 | |||||
| Result Name | Fetal Hemoglobin | |||||
| UofM | ||||||
| Result LOINC | 28067-7 | |||||
| Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
|---|---|---|---|---|---|---|
| Reflex 1 | 510206 | AChE+Hb F | 510173 | Interpretation | 76479-5 | |
| Reflex 1 | ||||||
| Order Code | 510206 | |||||
| Order Name | AChE+Hb F | |||||
| Result Code | 510173 | |||||
| Result Name | Interpretation | |||||
| UofM | ||||||
| Result LOINC | 76479-5 | |||||