The Study of Congenital Hypothyroidism Prevalence Using Screening in Azarshahr, East Azerbaijan Province, Iran, 2011

Background and objectives : Congenital hypothyroidism (CH) is one of the most prevalent causes of mental retardation which is preventable provided that earlier diagnosis and treatment are performed. The aim of this study was to investigate the prevalence of congenital hypothyroidism among newborns in Azarshahr during 2011. Material and Methods : This cross-sectional study was conducted on 1775 newborns in Azarshahr applying census method. In this regard, four drops of blood samples were taken preferably from each 3-5 day-old newborn’s heel using auto-lancet and then transferred to Whatman® 903 filter papers. Samples were checked to measure TSH level using ELISA method. Results : Program covering percentage was 95.9%. The disease prevalence was 1.12 per 1000 live births or one case per 887 live births. According to the results, 52.4% of the newborns were male. Samples in 84.6% of newborns were taken within 3rd-5th days of life and in 14.8%, within 6th-21st days of life. The TSH level in 97.5% of screened newborns was lower than 5 mu/L and in 1.6% of the samples was within the range of 5-9.9 mu/L. Recall rate was 1.7% and among them, two patients with hypothyroidism were found. The average age of treatment onset in patients was 20.5 days. Conclusion : Because of high prevalence of hypothyroidism in Azarshahr in comparison with other areas of Iran and the world, it is necessary to continue screening program.