Prognosis of patients with unilateral renal agenesis.

The clinical course was reviewed in 157 patients with unilateral renal agenesis and a normal contralateral kidney for the purpose of establishing a prognosis. There were 85 males (54%) and 72 females (46%). The mean age at diagnosis of unilateral renal agenesis was 37 years. The mean years at risk was 56. Proteinuria (> 150 mg/24 h) was found in 19% of the 37 patients tested (P < 0.001), hypertension developed in 47% of the 47 patients tested (P = 0.010), and renal function (adjusted for age and sex) was decreased in 13% of the 32 patients tested (P = 0.001). An increased filtration fraction was found in 7 (54%) of 13 patients evaluated. At the completion of this study, 114 patients (73%) were alive, and the survival rate was similar to that of age-, sex-matched United States life tables. Forty-three patients (27%) died; 6 deaths (4%) were caused by renal failure. Our review indicates that patients with unilateral renal agenesis and a normal solitary kidney are at increased risk of proteinuria, hypertension, and renal insufficiency. Therefore, it is essential to have prolonged and careful follow-up and to employ strategies that maximize renal preservation.