Screening for Congenital Hypothyroidism in East Azerbaijan province, IRAN

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 2009-2010. This descriptive analytic study was performed by using census cross- sectional method on 62459 neonates in East Azerbaijan province from 21st March 2009 to 20th March 2010. Blood samples were taken within the 3rd -5th days of life by lancet sticking of neonatal heel and transferred to filter papers for measuring TSH level. In the case of TSH ≥ 5mu/l, additional confirmation tests were done and confirmed cases based on serum confirmation test (TSH>10 mu/l or T4<6.5mg/dl) underwent treatment according to the national guidelines. Data were analyzed by SPSS software. The recall rate was 2.5%. Total number of patients was 94, including 55 males (58.5%) and 39 females (41.5%). Prevalence in males, females and overall was respectively 1:588, 1:769 and 1:666, with no significant difference. Seasonal prevalence was respectively 1:833, 1:943, 1:492 and 1:588 that shows no significant difference among four seasons. The highest prevalence was in Tabriz (27.7%) and the lowest in Azarshahr (0%) and Kaleibar (0%). Mean maternal age of affected neonates was 26.22 ± 6.2 years. Mean neonate's weight was 3500 ± 652 grams. In 76% of neonates time of sampling was in the 3rd -5th days of life and in 89% of them test result was announced before 13th day. Mean treatment onset based on neonate's age was 2.7±1 day. In 97.5% of screened neonates TSH level was less than 5 mu/l. 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.