Prenatal ultrasonic detection of anomalies with a lethal or disastrous outcome.

Although rare, a number of fetal anomalies can be detected with ultrasound in which the prognosis is either fetal death or minimal development. Anomalies of this type include anencephaly, holoprosencephaly, hydranencephaly, iniencephaly, cystic hygroma with hydrops, cystadenomatoid malformation of the lung with hydrops, conjoined twins of some types, renal agenesis, bilateral renal dysplasia, lethal dwarfing syndromes, and some forms of hydrops. Syndromes in which the severe form only are fatal include intracranial teratoma, encephalocele, pentalogy of Cantrell, vein of Galen aneurysm, the limb body wall complex, and infantile polycystic kidney. Sonographic findings of these conditions and other rarer lethal lesions are reviewed.