[The value of radiological and ultrasound examination in the prenatal diagnosis of the siren syndrome (author's transl)].

A sirenomelia is described. In addition to the characteristic single lower extremity, there are also, as in all cases of sympodia, severe malformations in the urogenital system, intestine, pelvis and vertebral column. The various theories of genesis are discussed. Ultrasound can be used as a screening procedure in early detection of deformities. So it is possible to avoid an emergency sectio in cases, where a non-viable child is endangered by intrauterine asphyxia.