شيوع بالاي كم كاري مادرزادي تيروييد در شهر اصفهان

High prevalence of congenital hypothyroidism in Isfahan, Iran

Introduction: Hypothyroidism is one of the preventable causes of mental retardation, which according to its clinical manifestations within the neonatal period, can be diagnosed in only fewer than 10% of cases. Delayed diagnosis results in irreversible cerebra-auditory complications unless the problem is diagnosed by screening programs. Materials and Methods: From May to December 2002, T4 and TSH concentrations of 20,000 serum samples obtained from newborns on 3rd-7th day of birth, born in seventeen hospitals throughout Isfahan were measured by RIA and IRMA, respectively. The newborns with abnormal screening results (TSH> 20 mlU/L, T4<6.5 pgIdL and based on the weight) were re-examined. Newborns with TSH >10mIU/L and T4<6.5 miug/dL on the second measurement were considered to be hypothyroid so treatment was begun. After performing complementary tests, the hypothyroid patients received replacement therapy with levothyroxine. Results: From 20,000 neonates that were examined, 531 were recalled (Recall rate = 2.65%) and 54 newborns were diagnosed as hypothyroid. The prevalence of neonatal hypothyroidism was estimated to be 11370. Conclusion: Considering the high prevalence of the disease in the population, the necessity of routine neonatal screening programs is underscored.