[Prenatal diagnosis of abnormalities of the neuroectodermal tube. Limitations of the assay of amniotic alpha fetoprotein and acetylcholinesterase and value of the qualitative study of cholinesterases. Apropos of 6 cases of anencephaly].

Measurement of amniotic fluid alpha-foetoprotein and acetylcholinesterase for the detection of neural tube defects has been used in 285 normal or neural tube defects affected pregnancies: 18 false positive results (with non neural tube defects fetal malformations) have been reported. A qualitative polyacrylamide gel electrophoresis technique has been used to identify the acetylcholinesterase isoenzyme derived from foetal cerebrospinal fluid. Results illustrate the value of amniotic fluid acetylcholinesterase electrophoresis. Amniotic cholinesterase presence may serve as a valuable marker for the detection of neural tube defects.