Anomalies of the fetal skeleton: sonographic findings

Malformations of the fetal skeleton can be classified into two major categories. The generalized skeletal dysplasias are characterized by abnormalities in multiple bones throughout the fetus. In contrast, focal skeletal abnormalities manifest a variable pattern both in distribution and extent of involvement. This pictorial essay illustrates the primary sonographic findings that indicate the presence of a skeletal abnormality. The major and minor sonographic features that allow formation of a reasonable differential diagnosis are also considered.