Reversible hydronephrosis in the neonate with urinary sepsis.

Hydroureteronephrosis without vesicoureteral reflux or lower-urinary-tract obstruction is uncommon in infants. There has been considerable interest in and controversy over the cause and management of this entity. We have cared for three neonates with severe hydroureteronephrosis after acute urinary tract infections, who were treated without operation.