Access to antenatal healthcare and the prevalence of oral clefts: a spatial analysis.

Congenital anomalies are caused by a variety of risk factors, including individual and environmental ones. This study estimated the prevalence of oral clefts and examined their area-level risk indicators using data from The National Congenital Anomaly Survey in South Korea. Disease mapping and ecological regression were used to assess the geographical variation and potential risk indicators for oral clefts, such as living in a rural area, material deprivation, and limited access to antenatal healthcare. In South Korea, 1.15 (95% CI, 1.08-1.23) children out of every 1,000 births were born with oral clefts during 2005 and 2006. The most common oral cleft type was cleft palate, followed by cleft lip, then cleft lip and palate. Disease mapping showed that the proportion of areas with a higher risk than the national average was relatively higher for oral clefts than for all congenital abnormalities among rural and healthcare underserved areas. The relative risk of oral cleft prevalence was higher in rural areas and healthcare underserved areas than in urban areas and areas with better access to healthcare. The findings suggest that access to antenatal healthcare as well as area-level risk indicators should be considered a priority when developing measures to decrease the occurrence of oral clefts.