[The prenatal diagnosis of hydronephrosis, when and why to operate?].

OBJECTIVES

To review the evaluation and management of the neonate and infant with prenatally detected hydronephrosis caused by a presumed ureteropelvic junction obstruction.

METHODS

The literature is reviewed and the arguments in favor of expectant observation versus early operation are discussed.

RESULTS

The meaning and severity of prenatally diagnosed hydronephrosis is determined after birth by evaluating: 1) the overall condition of the child; 2) the degree of dilatation on the ultrasonogram; 3) the differential renal function in the renogram and 4) the pattern of the excretory curve after furosemide in the renogram.

CONCLUSION

It is understood that dilation per se does not mean obstruction but, if all other parameters indicate obstruction, we recommend early surgical treatment to prevent obstructive damage to the immature infant kidney and because better recovery of function is possible when surgery is done in the first year of life.