Assessment and management of newborn hydronephrosis.

The incidence of asymptomatic hydronephrosis in newborns is high. Despite extensive clinical and scientific research much controversy still exists about the assessment and management of hydronephrosis during infancy. Postnatal management demands a detailed prenatal history. Initial workup in newborns with unilateral hydronephrosis starts with a physical examination and sonography of the urinary tract on day 3-5. Grades 3 and 4 hydronephrosis are further investigated with a voiding cystourethrogram (VCUG) and diuretic renogram between weeks 4 and 6. An infant with an asymptomatic unilateral hydronephrosis of any grade, without urinary infection and stable washout, and stable normal differential function on serial controls can be managed conservatively. The goal of all therapeutic strategies in the management of newborn hydronephrosis is to select all infants with severe obstructive dilatation during serial follow-ups and to perform surgical repair before irreversible deterioration and functional renal damage occurs. Interdisciplinary cooperation between experienced pediatric urologists, nephrologist and radiologists is the basis for optimal decision making.