Predictive value of amniotic fluid cystatin C levels for the early identification of fetuses with obstructive uropathies.

Objective: To compare the diagnostic accuracy of cystatin C with that of creatinine in discriminating renal function in fetuses without ultrasononographic evidence of renal malformations from those with obstructive uropathies.

Design: Prospective, observational cohort study.

Setting: Prenatal morphologic and functional evaluation of fetal obstructive uropathies throughout pregnancy.