Dandy-walker malformation: prenatal diagnosis and outcome.

Prenatal ultrasound identified Dandy-Walker malformation (DWM) in ten singleton pregnancies with concurrent central nervous system (CNS) anomalies and extra-CNS anomalies in eight cases. DWM was confirmed by postnatal magnetic resonance imaging (MRI) or pathological examination in nine cases. Karyotypes were normal in the seven infants tested. Postnatal neurological and developmental testing in the five survivors showed a spectrum of clinical outcome from minor defects to severe handicap. Postnatal investigation also disclosed additional CNS and extra-CNS findings not detected on ultrasound, as did autopsy in the other five infants. However, ultrasound diagnosis of DWM is accurate and is an indication for exhaustive screening for concurrent anomalies both within and outside the CNS and in chromosome structure and number, as the prognosis is heavily dependent on associated malformations and karyotype.