[Prenatal diagnosis of congenital defects through the determination of alpha fetoprotein].

The prenatal diagnosis of neural tube defects is based on elevated alpha-fetoprotein (AFP) concentrations in the amniotic fluid as well as in the maternal serum. Amniocentesis has to be performed in those women who already gave birth to an affected child and have the high risk to bear another. On the other hand more than 90% of the newborns with anencephaly and spina bifida are born by mothers without any increased risk in anamnesis. Therefore maternal serum screening is indicated in all pregnant women to rule out a neutral tube defect. The pittfalls of a general serum screening are discussed an a survey of the datas from different international centers is presented.