[Cerebral malformations in the 30th-36th pregnancy week--diagnosis and consequences].

When serious cerebral malformations of the fetal cerebrum are diagnosed, the pregnancy is in most cases so far advanced, that termination would be difficult medically, controversial ethically and--depending on legislation--impossible legally. Most cerebral malformations associated with hydrocephalus appear late in the 2nd and early in the 3rd trimester. Routine pregnancy ultrasound scan of the fetal brain is difficult due to the dynamic changes in cerebral anatomy during normal pregnancy and due to the artefacts produced by intra-cranial reverberations. The concept that there is a "right time" for in utero diagnosis of fetal hydrocephalus is reviewed. Unequivocal early diagnosis is only possible in cases of anencephaly. 15 cases of severe cerebral malformations that were seen during prenatal ultrasound at Innsbruck University Hospital are presented "Nonaggressive Obstetric Management" as a novel and structured approach to such cases is discussed.