Descriptive epidemiology of cleft lip and cleft palate in Western Australia.

BACKGROUND The reported birth prevalence of orofacial clefts (OFCs) varies considerably. This study describes the epidemiology of OFCs in an Australian population. METHODS We studied infants diagnosed with cleft lip, with or without cleft palate (CL±P), and cleft palate only (CPO) since 1980 and reported to the population based Western Australian Register of Developmental Anomalies. We calculated prevalence rates by sex, Aboriginal status, geographic location, and socio-economic status. Associations between clefts and folate availability, pregnancy characteristics, pregnancy outcomes, other congenital anomalies, and age at diagnosis were also investigated. RESULTS From 1980 to 2009, 917 infants with CL±P (12.05 per 10,000) and from 1980 to 2004, 621 infants with CPO (10.12 per 10,000) were registered. Prevalence rates for CL±P and CPO were 1.9 and 1.3 times higher, respectively, for Aboriginal Australians. Additional anomalies were reported for 31% of infants with CL±P and for 61% with CPO; chromosomal anomalies and other specific diagnoses accounted for 46% and 66%, respectively, of those with CL±P and CPO with additional anomalies. Almost all (99.7%) children with CL±P were diagnosed before 1 year of age, but 12% of CPO diagnoses were made after 1 year of age; 94% of these diagnoses were of submucous clefts and bifid uvula. CONCLUSIONS These data provide a picture of the prevalence of OFCs in WA since 1980, and provide a useful reference for OFC data in Australia and internationally. The quality and completeness of the WARDA data are high, reflected in high prevalence rates, and proportions of clefts occurring with other anomalies.