Fetal hydrocephalus. Clinical significance of associated anomalies and genetic counseling: a pathological approach.

We report on a consecutive series of 94 cases of fetal hydrocephalus. Pathological and neuropathological findings have been thoroughly analysed in order to define more precisely the clinical significance of associated anomalies and their implications in genetic counseling. In 90.5% of cases, hydrocephalus was associated with other central nervous system (84%) or extra neural (56%) anomalies. True aqueductal stenosis occurred only twice in our series. In only 9 fetuses, hydrocephalus was an isolated finding, secondary to haemorrhage or infection. Since fetal hydrocephalus is an etiologically heterogeneous disorder, its recurrence varies greatly. Without a final diagnosis, based on well documented pathological data and cytogenetic studies, accurate genetic counseling and prenatal diagnosis in subsequent pregnancies would be impossible.