Congenital hypothyroidism screening for

K3. Kato, N., Ishii, S., Naruse, H., Irie, M., Arakawa, H., and Tsuji, A., Enzyme immunoassay of thyroid-stimulating hormone using dried blood samples. A simple technique of screening for congenital hypothyroidism. Anal. Lett. 13, 1555-1565 (1980). 

Delange F. Neonatal screening for congenital hypothyroidism results and perspectives. Horm Res 1997 48 51-61. 

Dussault JH. Screening for congenital hypothyroidism. Clin Obstet Gynecol 1997 40 117-23. 

Sources of imprecision in laboratories screening for congenital hypothyroidism Analysis of nine years of performance data. Clin Chem 1989 35 1701-5. 

LaFranchi S. American Academy of Pediatrics. American Thyroid Association. Newborn screening for congenital hypothyroidism Recommended guide-hnes. Thyroid 1993 3 257-63. 

The frequency of hypothyroidism has been studied in some specific circumstances in the United States. The chief among these has been congenital hypothyroidism, which has long been seen as one of the most common preventable causes of mental retardation. Screening for congenital hypothyroidism began in North America in 1972. Dussault et al. summarized the first miUion newborns screened at three sites in the United States and two in Canada. Primary hypothyroidism was identified in one in 4254 births secondary—tertiary hypothyroidism occurred in one in 100000 births. In addition, the prevalence of TBG deficiency was found to be one in 8913 births ishst et al., 1979). 

Screening for congenital hypothyroidism is mandatory throughout the United States. Most locales initially test dried filter paper blood spots for T4 and follow-up with TSH for results in the lowest decile. It is estimated that as many as 10% of cases may be missed initially, because of either absent abnormafities at birth or errors in sample processing (Rhead and Irons, 2004). 

Use of Screening for Congenital Hypothyroidism Results for Monitoring Iodine Deficiency... 

Zhan J-Y, Qin Y-F, Zhao Z-Y. Neonatal screening for congenital hypothyroidism and phenylketonuria in China. World J Pediatr. 2009 5(2) 136-9. 

SCREENING FOR CONGENITAL HYPOTHYROIDISM BENEFICIAL EFFECTS ON NEUROPSYCHOLOGICAL DEVELOPMENT... 

In summary, we can state that screening for congenital hypothyroidism has been very beneficial but there is still much work to be done to come to a final conclusion. We think that the recommendations stated at the last International Symposium on screening are very appropriate. "The... 

Chanoine, J.P., Boulvan, M., Bourdoux, P. et al.. Increase recall rate at screening for congenital hypothyroidism in breast fed infants bom to iodine overloaded mothers. Arch. Dis. Child. 63 1027 (1988). 

At the time of screening for congenital hypothyroidism, modifications of TSH (shift to high values) are more and more frequent as one proceeds from borderline to moderate iodine deficiency. 

The concept of hypersensitivity of the newborn to the effects of iodine deficiency has developed since the introduction of systematic neonatal screening for congenital hypothyroidism. Hypersensitivity was initially documented in conditions of extreme iodine deficiency in developing countries and was subsequently confirmed in areas with marginally low iodine intake, including in Europe. 

S.E. Jewell, W.J. Slazyk, S.J. Smith, and W.H. Hannon, Sources of Imprecision in laboratories screening for congenital hypothyroidism analysis of nine years of performance data, Clin Chem 35(8) 1701-1705(1989). 

D.A. Fisher, Screening for Congenital Hypothyroidism, Trends in Endocrinology and Metabolism 2(4) 129-133(1991). 

Virtually 1(X) % of Swiss newborns are screened for congenital hypothyroidism. In the Central Laboratory of the Swiss Red Cross in B e, which screens about one third of the babies bom in Switzerland, the recall rate for TSH values over 20 mU/1 was O.S to 0.6 per KXX) in 198S and 1986. After lowering the recall limit to 15 mU/1 the recall rate was 2.2 per KXX) in 1987. 

D.A. Fisher, J.H.Dussault, T.P. Foley Screening for congenital hypothyroidism results of... 

TSH NEWBORN MASS SCREENING FOR CONGENITAL HYPOTHYROIDISM AS THE MONITORING METHOD OF IODINE DEFICIENCY IN SOUTHERN POLAND... 

Screening for congenital hypothyroidism frequently shows transient abnormality of thyroid function. The newborn is very susceptible to iodide excess and in 70 % of the cases (1), the reason for transient hypothyroidism is iodine overload (2-3). A common cause may be X ray investigations with iodine products. Two newborns hospitalized in our Neonatal Intensive Unit presented with iodine overload from investigations, producing transient hypothyroidism. The hypothyroidism disappears with iodine elimination. In one case, the child were submitted at six months to another iodine overload without consequences. The thyroid tests show no change. Transient neonatal hyperthyrotropinemia may be due to iodine overload, and the search for its etiology is essential, because it allows one to stop the treatment. 

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