Screening for Congenital Hypothyroidism in East Azerbaijan province, IRAN

Background & Aims: Congenital hypothyroidism (CH) is one of the most common preventable causes of mental retardation throughout the world. The aim of this study was to investigate the prevalence of CH among newborns of East Azerbaijan province in ۲۰۰۹-۲۰۱۰. Methods: This descriptive analytic study was performed by using census cross- sectional method on ۶۲۴۵۹ neonates in East Azerbaijan province from ۲۱st March ۲۰۰۹ to ۲۰th March ۲۰۱۰. Blood samples were taken within the ۳rd -۵th days of life by lancet sticking of neonatal heel and transferred to filter papers for measuring TSH level. In the case of TSH  ۵mu/l, additional confirmation tests were done and confirmed cases based on serum confirmation test (TSH>۱۰ mu/l or T۴<۶.۵µg/dl) underwent treatment according to the national guidelines. Data were analyzed by SPSS software. Results: The recall rate was ۲.۵%. Total number of patients was ۹۴, including ۵۵ males (۵۸.۵%) and ۳۹ females (۴۱.۵%). Prevalence in males, females and overall was respectively ۱:۵۸۸, ۱:۷۶۹ and ۱:۶۶۶, with no significant difference. Seasonal prevalence was respectively ۱:۸۳۳, ۱:۹۴۳, ۱:۴۹۲ and ۱:۵۸۸ that shows no significant difference among four seasons. The highest prevalence was in Tabriz (۲۷.۷%) and the lowest in Azarshahr (۰%) and Kaleibar (۰%). Mean maternal age of affected neonates was ۲۶.۲۲ ± ۶.۲ years. Mean neonate's weight was ۳۵۰۰ ± ۶۵۲ grams. In ۷۶% of neonates time of sampling was in the ۳rd -۵th days of life and in ۸۹% of them test result was announced before ۱۳th day. Mean treatment onset based on neonate's age was ۲.۷±۱ day. In ۹۷.۵% of screened neonates TSH level was less than ۵ mu/l. Conclusion: The prevalence of CH in East Azerbaijan province is significantly higher than national and worldwide levels that requires continuation and reinforcement of neonatal screening programs. On the other hand, comprehensive and complementary studies for recognizing relevant factors are among priorities of health system research in this province.

Keywords:

Congenital hypothyroidism , Prevalence , mass screening , Newborn , East Azarbaijan