SHORTCOMINGS IN PREDICTING POSTNATAL RENAL-FUNCTION USING PRENATAL URINE BIOCHEMISTRY IN FETUSES WITH CONGENITAL HYDRONEPHROSIS

Ten fetuses with hydronephrosis underwent one to seven urine sampling procedures at 23 to 36 weeks' gestation to evaluate renal function. Po stnatally, the infants' renal function was assessed by a combination o f serum creatinine measurement, ultrasonography, and renal scintigraph y. Six infants had pyelo-ureteric junction obstruction, two had megabl adder with megaureter, and two had vesico-ureteric reflux. All infants had normal serum creatinine levels at the time of postnatal follow-up , but five of the seven with unilateral involvement had moderate or se vere renal damage. Abnormal urinary electrolyte concentrations were fo und antenatally in only two of them. For the three infants with bilate ral hydronephrosis, postnatal evaluation showed moderately or severely damaged kidneys despite prenatal evidence of normal biochemical index es. Fetal urine electrolyte measurement may be accurate in the diagnos is of renal dysplasia, but its sensitivity is poor in predicting moder ate renal dysfunction. Copyright (C) 1996 by W.B. Saunders Company