Epidemiology of Congenital Idiopathic Talipes Equinovarus in Iowa, 1997-2005

Congenital idiopathic talipes equinovarus (ITEV), also known as clubfoot, is a well-recognized foot deformity. To date, prevalence estimates and descriptive data reported for ITEV have varied due to differences in study methodology. Using population-based surveillance data collected by the Iowa Registry for Congenital and Inherited Disorders, we examined isolated ITEV births delivered from 1997 through 2005 and compared to live births in Iowa during the same time period. An overall prevalence was calculated for live, singleton full-term births only. Prevalence odds ratios (POR)s and 95% confidence intervals (CI)s were examined for selected infant and parental characteristics. The prevalence of isolated ITEV was 11.4 per 10,000 live, singleton full-term births (95% CI = 10.3, 12.6), with no significant variation in prevalence during the study period. Increased PORs were found for males (POR 1.8; 95% CI = 1.5, 2.3) and maternal smoking during pregnancy (POR = 1.5, 95% CI = 1.2, 1.9); low birth weight (<2,500 g) showed an increase among females (POR = 3.2, 95% CI = 1.5, 6.9) but not males (POR = 0.9, 95% CI = 0.3, 2.8). Elevated, but non-significant, PORs were found for season of birth, maternal education, and trimester prenatal care was initiated; decreased PORs were found for fetal presentation, maternal race/ethnicity, parity, area of residence, and parental age at delivery. Our study of a well-defined, homogenous sample suggested that prevalence of isolated ITEV in Iowa was similar to that reported in other population-based studies and provided support for some, but not all, previously reported associations with infant and parental characteristics. More detailed, longitudinal studies of isolated ITEV are recommended.