Western Australian Congenital Malformations Register.

The Western Australian Congenital Malformations Register, the first of its kind in Australia, was established in 1980, and records malformations occurring in children born on, or after, January 1, 1980. Multiple sources of notification are used, and diagnoses are validated and updated on an ongoing basis. Analysis of data from the first two years of operation showed a malformation rate of 4.3% in 1980 and of 3.8% in 1981. The labour-intensive nature of the Register ensures that the records are as complete and accurate as possible, and, therefore, form a reliable population-based data set for incidence, prevalence, and investigative studies of congenital malformations in Western Australia.