Three-dimensional ultrasound in diagnosing phocomelia.

Deformations of the extremities with limb reduction are rare congenital defects which affect one in 1692 live babies. Three-dimensional ultrasound can be of value in the prenatal diagnosis of such deformities. We present a case of upper phocomelia and congenital thrombocytopenia (TAR syndrome). Visualization of the upper extremities was achieved by three-dimensional ultrasound after surface and volume rendering. This new technique allows imaging not only of surfaces like the fetal skin, but also of internal structures like the fetal skeleton.