The presence of AChE in amniotic fluid is positive for a neural tube defect (open tube defects, and to a lesser degree, ventral wall defects) if fetal contamination can be ruled out.
A bloody tap may cause a false positive result.
8 - 15 days
Submit 1 ml of uncentrifuged amniotic fluid. Refrigerate. A specimen from the 16-18 week gestational period of pregnancy is preferred; from the 14-21 week is acceptable. GESTATIONAL AGE IS REQUIRED ON THE REQUISITION FOR PROCESSING.
Test sent to Mayo Medical Laboratories.