Incidence and Determinants of Birth Defects and Enzyme Deficiencies among Live Births in Oman: A review of the 2005 National Register

ObjectivesIn 2003, the Omani Ministry of Health Child Health Care Program initiated a national Birth Defects (BD) Register. This paper reviews the magnitude and risk factors of birth defects in children born and registered in 2005 using data from the BD Register.MethodsPediatricians and neonatologists examined children with BDs found either during screening at birth or when attending clinics in their first year of their life. Clinical examination, laboratory, sonographic and radiological investigations were carried out. A pre-tested form was used to note personal details, type of birth defect including International Classification of Diseases-10 (ICD-10) codes of BD and selected risk factors. The incidence rates per 100 live births were calculated.ResultsThe annual incidence of BD in Oman was 2.53% (95% CI 2.38–2.68). Males had a significantly higher risk of BD than females (relative risk (RR) = 2.0). The regional variation of BD was also significant (χ2 = 363). The incidence of anaemia due to enzyme disorders was 1.4%. BD of urogenital organs, hands and feet and Down’s syndrome were the main types of anatomical defects. Consanguinity among parents (RR = 0.85) and low birth weight (RR = 0.28) was negatively associated to birth defects. Mothers giving birth at gestational age of 37 weeks (RR = 1.89) had a higher risk of having children with BD. Maternal and paternal age were not associated to BD.ConclusionThe national Register for BD is an important evaluation tool. Both genetic and acquired risk factors seem to affect BD rates and types in Oman