Utility of a screening examination of the fetal extremities during obstetrical sonography.

The hands, feet, and long bones of the extremities were visualized and an image of the femur was obtained as part of a brief fetal anatomy survey during approximately 6,700 low-risk and high-risk obstetric sonograms. This examination identified four fetuses with five instances of isolated extremity abnormalities and nine fetuses with ten instances of generalized extremity abnormalities. Isolated abnormalities included malformation or complete or partial absence of an extremity. Generalized abnormalities included fused hands and feet, polydactyly, phocomelia, hyperechoic muscle with contractures, and several varieties of dwarfism. Most fetuses had other structural abnormalities as well and two had an abnormal family history. The sensitivity of the fetal anatomy survey for the detection of extremity malformations would not have been changed if the routine femur measurement had been retained but the systematic visualization of the fetal extremities had been done only in selected fetuses with a malformation of any kind or an abnormal family history.