Stability of prevalence rates of anorectal malformations in the Alberta Congenital Anomalies Surveillance System 1990-2004

Background/Purpose: Anorectal malformations appeared to be increasing in the province of Alberta, Canada. To assess whether this was a significant trend, with the possibility of these having a teratogenic origin, we examined the frequency of anorectal malformations over a 15-year period. Methods: We examined the records of the Alberta Congenital Anomaly Surveillance System, which is a semiactive surveillance system using the British Paediatric Association and the Royal College of Paediatrics and Child Health expansions of the International Classification of Diseases-Ninth Revision and the International Classification of Diseases-10th Revision. Results: The overall rate was 1/2162 (4.63/10,000 total births) with a marked male predominance (1.7:1). Approximately two thirds of the 273 cases had 1 or more malformations. Conclusion: Although there was an increasing trend in the rate from 1999 especially for the multiples, this was not significant. In view of the advances in syndrome identification and molecular diagnostics, consideration should be given to a detailed review of the family history and appropriate testing not only for multiple cases but also for isolated ones. (C) 2007 Elsevier Inc. All rights reserved.