Neonatal and early infancy management of prenatally detected hydronephrosis.

Hydronephrosis discovered during prenatal ultrasound will often resolve spontaneously; however, it should be evaluated in the postnatal period in a manner commensurate with its risk of renal injury. Early intervention is appropriate in cases of bladder outlet obstruction or the severely obstructed solitary kidney. In most other cases, it is both safe and reasonable to allow the possibility of spontaneous improvement with the intensity of follow-up based on the severity of the hydronephrosis. Clinical decision making should be a shared process between families and caregivers.