Serial sonographic features of a fetus with hydranencephaly from 11 weeks to term

Fetal hydranencephaly is a rare congenital cerebral abnormality characterized by complete or near complete absence of the cerebral cortex. We present the sonographic evolution of a case of fetal hydranencephaly from 11 weeks of gestation to term. At 11 weeks, the fetal head appeared small and the forehead was sloping. The normal cerebral hemispheres could not be identified. Follow-up sonography showed that the cerebral hemispheres were almost entirely replaced by fluid, except in the occipital region. The baby died 2 weeks after birth. Post-mortem examination confirmed the diagnosis of hydranencephaly.