USE OF THYROID-STIMULATING HORMONE TESTING IN NEWBORNS TO IDENTIFY IODINE DEFICIENCY

Iodine deficiency has traditionally been associated with goiter and cr etinism. More recently, iodine deficiency has been recognized as the l eading worldwide cause of preventable intellectual impairment. Intelle ctual and neurologic deficits occur because of a lack of thyroid hormo ne during critical phases of brain development. More sensitive biologi c tests may be useful in determining the true extent of iodine deficie ncy in populations. Thyroid stimulating hormone (TSH) levels among urb an newborns from countries with known iodine deficiency problems were determined using a sensitive whole-blood spot assay. Results found pre valences of high TSH (>5 mu/L whole blood units using a sensitive mono clonal assay) ranging from 32-80% compared with a prevalence of 3% usu ally found in iodine-replete areas. These; findings suggest that devel oping brains of newborns are at risk from the detrimental effects of i odine deficiency in these urban areas. The results presented suggest t he need for effective intervention programs in urban areas as well.