Caudal regression or caudal dysplasia sequence (CDS) is a rare congenital malformation, which includes a wide spectrum of musculoskeletal abnormalities involving the lumbosacral spine, pelvis and lower limbs. It can be associated to visceral defects in various degrees. Maternal diabetes, genetic predisposition and vascular hypoperfusion have been suggested as possible causative factors. Women with diabetes who are dependent on insulin are 200–400 times more likely to have a child with caudal regression, making CDS the most characteristic fetal abnormality of diabetic embryopathy. Prenatal diagnosis is possible by ultrasonographic examination. The sonographic findings include abrupt interruption of the lumbar spine and ‘Buddha or frog position’ of the lower limbs. MRI has demonstrated the level of the vertebral anomalies as well as the associated abnormalities and this is crucial because the prognosis of this condition depends on the severity of the lesion and the presence of associated disorders.
