Figure 1. The unrelenting progression to end-stage kidney disease was encountered in a majority of children after neonatal release of posterior urethral valves. Serum creatinine concentrations rose to 2.5 mg/dl in 3.95 years and doubled again in 7.95 years. From Roth KS, Carter WH Jr, Chan JCM: Obstructive nephropathy in children: Long term progression after relief of posterior urethral valve. Pediatrics 2001; 107: 1004-1010. [By permission of American Academy of Pediatrics].