Acetylcholinesterase, Amniotic Fluid (AChE-C, AChE-R, AChE-RS)
Prenatal Screening Laboratory
Polyacrylamide gel electrophoresis
Specimen Required:
Amniotic fluid: 2 mL
Refer to Special Handling Requirements
Days Test Set Up:
Monday - Thursday
Analytic Time:
3 days
Reference Values:
No visible acetylcholinesterase (AChE) band = Normal.
Visible pseudocholinesterase (PChE) band = Normal.
Applies to 14 - 25 weeks gestation
CPT Code(s):
82013, 82143, 82664
Relevance:
The presence of AChE in amniotic fluid can confirm open fetal defects such as anencephaly, spina bifida, gastroschisis, or omphalocele.
Notes:
If a visible AChE band is present, the sample will be re-assayed with a specific inhibitor to AChE. Additionally, all AChE positive samples are examined reflexively (no surcharge) to rule out contamination by fetal blood or bovine serum albumin. All confirmed positive samples are densitometrically scanned to determine the ratio of AChE to PChE. This ratio is useful in distinguishing open neural tube defects (ONTD) from open ventral wall defects (OVWD). If requested, abnormal results are telephoned to the referring physician's office or laboratory.
Reference(s)