Talipes equinovarus in Western Australia.

In Western Australia (WA), talipes equinovarus is a notifiable birth defect and, since 1980, has been ascertained by the population-based Birth Defects Registry (BDR). Talipes equinovarus deformities were classified as two distinct and distinguishable types, viz. isolated talipes equinovarus (no other birth defects present) and associated talipes equinovarus (other birth defects present). The birth prevalence of associated talipes in WA between 1980 and 1994 was 0.90 per 1000 births, and of isolated talipes was 1.25 per 1000 births. The rate of the isolated deformity was higher in Aboriginal infants (3.49 per 1000 births) than in Caucasian infants (1.11 per 1000 births) and non-Aboriginal non-Caucasian infants (0.73 per 1000 births). The sex differential in the rate of the isolated deformity was greatest among Aboriginal infants, with the rate in males being almost four times that in females. The birth prevalence of both types of the deformity remained stable over the 15-year study period. The rate of caesarean and breech deliveries and the proportion of bilaterally affected feet was greater among infants with associated talipes equinovarus deformity. An accurate and complete identification of cases of isolated talipes equinovarus in the 1980-94 WA birth cohort provides a basis for furthering the understanding of the epidemiology and hence the aetiology of the deformity.