Gel electrophoresis of amniotic-fluid acetylcholinesterase and open neural tube defect
Ko, T.M.; Hsieh, F.J.; Lee, T.Y.
Journal of the Formosan Medical Association 85(10): 993-999
1986
ISSN/ISBN: 0371-7682 PMID: 2434604 Document Number: 269227
A total of 740 samples of amniotic fluid, including 15 with fetal neural tube defects (NTD), 9 with intrauterine fetal death (IUFD), and 34 with other fetal anomalies, were studied for acetylcholinesterase (AChE) by 7% vertical slab polyacrylamide gel electrophoresis. All 15 samples with fetal open NTD had AChE band. Of 9 samples with IUFD, 2 clear fluids were negative for AChE band while the other 7 brownish fluids were positive for AChE band. Among the 34 samples from other fetal anomalies, only 2 blood-contaminated samples from Hb Bart's hydrops fetalis and one from threatened abortion with intraamniotic bleeding had AChE band. Of the 549 samples obtained from normal pregnancy before the 28th gestational week, only one had AChE band, a false positive rate of less than 0.2%. Seven samples with normal fetal outcome had significantly elevated alpha-fetoprotein (AFP) level but AChE band was absent. AChE gel test was a highly sensitive and specific adjuvant assay for the prenatal diagnosis of fetal open NTD. Amniotic fluid with elevated AFP should be checked with gel electrophoresis for AChE.