Antenatal diagnosis and obstetric management of Dandy-Walker syndrome.

Real-time ultrasound equipment has the potential for investigating the fetal neural axis and allows the diagnosis of many anomalies arising from this area. Five cases of Dandy-Walker syndrome, one of the major causes of congenital hydrocephalus, were diagnosed antenatally. In all cases ultrasound allowed specific recognition of the defect in the cerebellar vermis. This defect connected the fourth ventricle to a posterior fossa cyst in four cases and to an occipital meningocele in one case. In three cases the diagnosis was made prior to viability, and the parents elected termination of pregnancy. In two cases recognized in the third trimester, neurosurgical care was provided soon after delivery.