Test Details
Methodology
Chromosome analysis: in situ cell culturing of amniocytes for the investigation of numerical and/or structural chromosome abnormalities; chemiluminescent immunoassay for AFP
Result Turnaround Time
10 - 14 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
Chromosome analysis; amniotic fluid and amniotic fluid AFP. Samples with AFP values ≥2.0 MoM will reflex to determination of acetylcholinesterase and fetal hemoglobin to rule out open neural tube defects.
Use
Prenatal detection of chromosome abnormalities in at-risk pregnant women. AFP analysis of midtrimester amniotic fluid for detection of open neural tube and ventral wall defects. This test reflexes to AChE and fetal hemoglobin if AF-AFP is abnormal. While chromosome analysis is being performed, additional biochemical or molecular analysis can be performed.
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. AChE false-positive and false-negative results are more frequent at gestational ages of less than 13 weeks or greater than 24.9 weeks.
If prior NIPT studies have been performed, include copy of the report.
Limitations
No amniocytes in fluid; failure of cells to grow in culture and/or contamination (eg, by Mycoplasma) precludes analysis. Overall culture success rate has been reported as 99% with a fetal loss (within four weeks of the amniocentesis) of 0.5%.
Specimen Requirements
Specimen
Amniotic fluid
Volume
20 to 30 mL
Minimum Volume
10 mL (Minimum volume may delay results as fewer cells may be available for cell growth.)
Container
Sterile plastic conical tube; do not use urine containers or tubes with rubber stoppers. Rubber is toxic to amniocytes.
Collection Instructions
Discard first 2 mL of fluid aspirated to avoid maternal cell contamination. Specimen is collected in a 20 mL sterile syringe and transfer aseptically to sterile tubes. Remove needle from syringe after collection. The test request form is completed and accompanies specimen and miscellaneous slip to the laboratory.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 1 month |
Storage Instructions
Maintain specimen at room temperature. Do not freeze or refrigerate.
Causes for Rejection
Specimen found not to be amniotic fluid; gross contamination with red cells; frozen specimen; nonsterile container; container with rubber stopper (rubber is toxic to amniocytes)
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 510185 | Chromosome, AFP, Amniotic Fl | 010806 | AFP, Amniotic Fluid | N/A | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 101352 | AFP Value | ug/mL | 1832-5 | |
| 510185 | Chromosome, AFP, Amniotic Fl | 101360 | AFP MoM | 29253-2 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 101379 | Gestational Age(Wks) | 49051-6 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 101378 | Interpretation | 41273-4 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 101376 | Director | 72486-4 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 999500 | Amniotic Fluid, AFP | N/A | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052138 | Cells Counted | 64095-3 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052139 | Colonies | 64096-1 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052140 | Cells Analyzed | 64092-0 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052141 | Cells Karyotyped | 64091-2 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052143 | GTG Band Resolution Achieved | 64093-8 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052144 | Cytogenetic Diagnosis | 62356-1 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052033 | Cytogenetic Interpretation | 62357-9 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052146 | Specimen Type | 48002-0 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 052034 | Director Review: | 48672-0 | ||
| 510185 | Chromosome, AFP, Amniotic Fl | 512123 | 11502-2 | |||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 010806 | |||||
| Result Code Name | AFP, Amniotic Fluid | |||||
| UofM | ||||||
| Result LOINC | N/A | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 101352 | |||||
| Result Code Name | AFP Value | |||||
| UofM | ug/mL | |||||
| Result LOINC | 1832-5 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 101360 | |||||
| Result Code Name | AFP MoM | |||||
| UofM | ||||||
| Result LOINC | 29253-2 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 101379 | |||||
| Result Code Name | Gestational Age(Wks) | |||||
| UofM | ||||||
| Result LOINC | 49051-6 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 101378 | |||||
| Result Code Name | Interpretation | |||||
| UofM | ||||||
| Result LOINC | 41273-4 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 101376 | |||||
| Result Code Name | Director | |||||
| UofM | ||||||
| Result LOINC | 72486-4 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 999500 | |||||
| Result Code Name | Amniotic Fluid, AFP | |||||
| UofM | ||||||
| Result LOINC | N/A | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052138 | |||||
| Result Code Name | Cells Counted | |||||
| UofM | ||||||
| Result LOINC | 64095-3 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052139 | |||||
| Result Code Name | Colonies | |||||
| UofM | ||||||
| Result LOINC | 64096-1 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052140 | |||||
| Result Code Name | Cells Analyzed | |||||
| UofM | ||||||
| Result LOINC | 64092-0 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052141 | |||||
| Result Code Name | Cells Karyotyped | |||||
| UofM | ||||||
| Result LOINC | 64091-2 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052143 | |||||
| Result Code Name | GTG Band Resolution Achieved | |||||
| UofM | ||||||
| Result LOINC | 64093-8 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052144 | |||||
| Result Code Name | Cytogenetic Diagnosis | |||||
| UofM | ||||||
| Result LOINC | 62356-1 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052033 | |||||
| Result Code Name | Cytogenetic Interpretation | |||||
| UofM | ||||||
| Result LOINC | 62357-9 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052146 | |||||
| Result Code Name | Specimen Type | |||||
| UofM | ||||||
| Result LOINC | 48002-0 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 052034 | |||||
| Result Code Name | Director Review: | |||||
| UofM | ||||||
| Result LOINC | 48672-0 | |||||
| Order Code | 510185 | |||||
| Order Code Name | Chromosome, AFP, Amniotic Fl | |||||
| Order Loinc | ||||||
| Result Code | 512123 | |||||
| Result Code Name | ||||||
| UofM | ||||||
| Result LOINC | 11502-2 |
| 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 | |||||