[The usefulness of the level of alpha-fetoprotein (AFP) and electrophoresis of amniotic acetylcholinesterase for the detection of selected congenital malformations].

We report the experience of a prenatal diagnosis center for routine amniotic alpha-fetoprotein and acetylcholinesterase analysis during the second trimester of pregnancy in 4,411 pregnant women. The identification of neural tube defects, for a population with a low prevalence, and of other major birth defects was studied. The pertinence of practising a fetal karyotype when these tests were abnormal was also estimated. For amniotic acetylcholinesterase, 262 electrophoreses were done. Sensitivity, specificity and positive predictive values of the tests were calculated. One fetus out of 4 carries an unbalanced chromosomal anomaly if amniotic alpha-fetoprotein is higher than the mean plus 2 standard deviations. This result shows the need for a fetal karyotype for all these cases.