Screening for congenital hypothyroidism in Turkey

Abstract

A pilot study was performed to determine the incidence of congenital hypothyroidism (CH) in Turkey and to build a model for nationwide screening. From December 1991 to December 1992, 30,097 newborns were screened for CH using a primary measurement of thyroid stimulating hormone in capillary blood on days 3-5 of life. Samples were obtained in collaboration with the ongoing nationwide phenylketonuria screening programme. Eleven cases of primary CH were detected giving the incidence of 1:2736. Recall rate was 2.3%. Replacement therapy with L-thyroxine was started after the confirmation of diagnosis. The median age at the initiation of replacement therapy was 23 days (range 7-35 days).

Conclusion: The incidence of CH is notably higher in Turkey than reported in most other countries. Iodine deficiency and/or dyshormonogenesis might contribute to this high incidence. This result emphasizes the necessity of a nationwide screening programme.