Abdominal distention and renal failure in a neonate.

A term male neonate presented to his paediatrician for a routine follow-up after hospital discharge. Prenatal care had been excellent and labour and delivery had been unremarkable. He had been feeding, gaining weight and was not in distress though significant abdominal distention was noted. Lab tests revealed electrolytes derangements, metabolic acidosis and renal failure. An ultrasound revealed severe unilateral hydronephrosis and echogenic kidneys. A voiding cystourethrogram revealed the definitive diagnosis which was posterior urethral valves.