[Prenatal ultrasonographic diagnosis of malformations of central nervous system (author's transl)].

More than 90 per cent of all malformations in the central nervous system can now be prenatally identified by combination of various diagnostic methods. The greatest value of all should be attributed to ultrasonography. An analysis was made of 23 malformations in the central nervous system with regard to their obstetric consequences. Conservative management of pregnancy followed by immediate paediatric surgical treatment of the newborn, delivered on term, can be justified only for hydrocephalus below the 90th percentile with no additional malformation, beyond the 35th week of pregnancy, and for minor dorsal fissurations in distal regions. Medical termination of pregnancy must be the obstetric consequence in all other cases, because of the severity of the defect and its poor prognosis.