[Prenatal diagnosis of neural tube and abdominal wall defects in the 2d trimester].

Combined alpha-fetoprotein screening in serum and specified sonographic examination has proved useful in prenatal diagnosis of neural tube and abdominal wall malformations. 207 amniocenteses were performed within a period of 3 years due to pathologic serum alpha-fetoprotein values and/or abnormal sonographic findings. 101 amniotic fluid specimens showed an increase of alpha-fetoprotein of more than 2.5 times the average value. 60 malformed neural tubes, 17 foetuses with abdominal wall defects, as well as 2 other malformations, were diagnosed. "Open" defects, as well as 17 false positive AFP values, were discovered through the electrophoretic presence of ZNS-specific acetylcholinesterase in the amniotic fluid.