Screening for congenital hypothyroidism in Kashan, Iran

Background and Çongenital Hypothyroidism (ÇH) is one of the preventable causes of mental retardation, which according to its clinical manifestations within the neonatal perioid, can be diagnosed in only fewer than 10% of cases. Delayed diagnosis results in irreversible cerebro-auditory complications unless the problem is diagnosed by screening programs. From May to December 2003, serum T4 and TSH concentrations of 3005 newborns on the 3rd - 7th day of their birth were measured by RÏÂ and ÏRMÂ, respectively in all Kashan hospitals. The newborns with abnormal screening results were reexamined (TSH> 20 mÏÜ/L, T4<6.5 μg/dl and based on the weight). Newborns with TSH >10 mÏÜ/L and T4<6.5 μg/dl on the second measurment were considered to be hypothyroid. Âfter performing complementary tests, replacement therapy with levothyroxine was begun in neonates with ÇH. From 3005 neonates, 51 newborn were recalled (recall rate = 1.7%) and 10 newborns were diagnosed as hypothyroid cases. The prevalence of neonatal hypothyroidism was estimated to be 1 / 303. Çonclusion: Çonsidering the high prevalence of ÇH in the population, the necessity of routine neonatal screening programs is emphasized.