[Congenital malformations of the urinary tract. Rational postpartum diagnosis].

More than one third of the anomalies diagnosed antenatally by ultrasound comprises the urinary tract. The criteria of the diagnostic and therapeutic approach, which resulted from our experience in children with symptomatic urinary tract anomalies cannot be necessarily applied to asymptomatic newborns. Not all urinary tract anomalies are obstructive and need surgical correction. Therefore, rational diagnostic approach after birth is necessary, which starts with ultrasonography. The first radiological diagnostic procedure is always a voiding cystourethrography in order to diagnose or exclude infravesical obstruction or a vesicoureteric reflux. The dynamic radionuclide nephrography (123I-Hippuran) under standardized conditions with adequate hydration and Furosemide-induced diuresis is able to detect a significant obstruction at the pelvi-ureteric or uretero-vesical junction. The intravenous urography is limited to specific questions and a computerized tomography is rarely indicated. In rare cases when dynamic investigations are equivocal, antegrade pressure flow studies according to Whitaker can be reliably exclude or prove obstruction.