Geographical distribution of congenital heart defects in Saudi Arabia

BACKGROUND: Congenital heart defects (CHD), which are caused by abnormalities early in fetal life, encompass over 50 diagnoses. Since the detailed etiology is unknown, the geographical distribution of defects might suggest likely risk factors. METHODS: The geographical distribution of 5 865 Saudi Arabian nationals with CHD was studied by cross-matching their residential provinces and towns with a geographical information system provided by the General Directorate for Military Survey. Population data were obtained from the 1413H census. RESULTS: CHD cases were mostly distributed across the provinces in proportion to their total population but due to their size and inhomogeneity, province-based thematic maps were found to be misleading. City-based maps were preferable and showed similar geographic distributions for cases registered in successive years. Thematic maps of the distribution of the CHD burden highlighted the southwestern provinces, near the border with Yemen, and the northeast section of the Eastern Province. CONCLUSIONS: Patterns of disease in Saudi Arabia are best studied at the level of individual towns and villages. The CHD registry has already attained good national coverage and can therefore support nationwide epidemiological studies. Southwestern Saudi Arabia and the northern part of the Eastern Province appear to exhibit a higher burden of CHD.