Prenatal diagnosis of cervical ribs by three-dimensional ultrasound in a foetus with a herniated Dandy-Walker cyst.

We present a case report of a foetus with a herniated Dandy-Walker cyst and bilateral rudimentary cervical ribs. The cervical ribs were visualised prenatally by three-dimensional ultrasound and confirmed by post-termination radiography. The prevalence of cervical ribs is higher in deceased fetuses and neonates with or without structural abnormalities compared with healthy individuals and might be regarded as a marker of disadvantageous fetal development. We demonstrate that evaluation of the fetal vertebral pattern by three-dimensional ultrasonography, including the cervical region, is feasible and could provide valuable information regarding fetal and neonatal prognosis.