Ninety-five gravidae were examined at Düsseldorf University Gynecological Clinic for assessment of the fetal renal system. Suspected disorders were ruled out in 33 cases by sonography. Urogenital malformations without major loss of function were diagnosed in 25 fetuses. The prognosis was unfavorable in 15, and 22 fetuses had other disorders. In 5 out of 22 infants on whom autopsy was performed, the kidneys were found to be normally developed, contrary to the sonographic diagnosis. However, all five of these infants had anomalies of the umbilical artery. It is well known that cases of anhydramnios in the first half of pregnancy have a poor prognosis. In order to assess such cases better, the authors consider the following examination procedure appropriate: 1) filling with amniotic fluid; 2) Lasix provocation test; 3) thorough sonographic examination of the fetus; 4) karyotyping; and 5) identification of maternal infections. It is at present impossible to say whether there is a statistical relationship between changes in the umbilical cord and disorders of renal function.