Test Description:
The measurement of amniotic fluid alpha fetoprotein (AFAFP) and acetylcholinesterase (AChE) along with ultrasound are considered diagnostic for open fetal defects. This testing is recommended when there is concern about an open fetal defect due to results of a maternal serum AFP screen, findings on an ultrasound examination or family history information. AFAFP levels above 2.0 MoM are considered abnormal. Approximately 90% of open neural tube defects are detected with AFAFP alone, while 98% are detected with a combination of AFAFP and acetylcholinesterase (AChE) testing. The detection rate for anencephaly is even higher. Amniotic fluid AFP results can be reported in MoM levels from 15 to 24 weeks 6 days gestation.
Methods:
Quantitative determination of alpha fetoprotein (AFP) in amniotic fluid by chemiluminescent immunoassay using the Beckman Coulter Access System.
Specimen Requirements:
Unspun amniotic fluid aliquots are received through the MSU Cytogenetics Laboratory. Amniotic fluid color and the presence of any visible blood should be noted on the requisition form; reddish or brown discoloration may indicate the presence of maternal or fetal blood contamination that may falsely elevate AFAFP. For specimen requirements, call (517)353-2032 or (877) TEST-DNA.
Shipping Instructions:
AFP in amniotic fluid is not as stable as in maternal serum. Amniotic fluid samples should not be exposed to high temperatures or held at room temperature any longer than necessary. Ship immediately or via overnight delivery to the MSU Cytogenetics Laboratory, B123 Life Sciences Bldg, East Lansing, MI 48824. To arrange shipment, call (517) 353-2032 or (877) TEST-DNA.
Turnaround Time: 1-2 days following receipt of sample
Test CPT Code: 82106
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