4-5 days; 4-7 days for AChE if reflexed from AFP
Specimens should be shipped at room temperature in a leak-proof, rigid container with overnight delivery. To discuss minimum acceptable specimens, please contact Allele Diagnostics.
- Amniotic fluid: 2.5 mL whole fluid
82013 (if reflexed), 82106 x1, 83033 (if reflexed)
- Increased maternal serum alpha fetoprotein; increased risk for ONTD on maternal serum screen.
- Prenatal diagnosis of open neural tube defect (ONTD) at 14-25 weeks gestation in the general population.
- Patients at an increased risk of ONTD due to family history, use of specific medications, or diagnosis of diabetes.
- Ultrasound finding suggestive of ONTD or abdominal wall defect.
Alpha Fetoprotein (AFP) measurement with reflex to acetylcholinesterase (AChE) when AFP is increased.The test is performed using an immunoenzymatic assay to determine the range of AFP present in amniotic fluid. The normal range is highly dependent on a correct gestational age. If the AFP is elevated, then testing to evaluate the presence or absence of acetylcholinesterase and/or fetal hemoglobin via gel electrophoresis will be added for an additional charge. The presence of acetylcholinesterase in amniotic fluid is consistent with an open neural tube defect and possibly abdominal wall defects, to a lesser extent. Acetylcholinesterase and fetal hemoglobin testing requires an additional 4-7 days to be reported.