Renal agenesis in British Columbia.

We review the incidence of bilateral and unilateral renal agenesis occurring in more than 625,000 consecutive births in British Columbia from 1952 to 1982. In total, 92 cases of bilateral renal agenesis and 117 cases of unilateral renal agenesis were identified. Congenital anomalies occurring in association with these conditions were also analyzed. The findings of the study support a mechanism in at least a proportion of cases of a primary developmental defect involving multiple systems within the fetus, with oligohydramnios being the result of the syndrome not the cause. Oligohydramnios no doubt contributes to the anomalies of the face, musculoskeletal system, and genitalia. No trends in changing incidence over time were identified.