CONGENITAL HYPOTHYROIDISM SCREENING RESULTS IN THE TURKISH PROVINCE OF ADIYAMAN IN 2015-2020.

Context: Congenital hypothyroidism (CH) is one of the most common preventable causes of intellectual disability, and can be diagnosed in the early period through neonatal screening programs.

Objective: The purpose of this study was to determine the prevalence of CH and recall rates in the province of Adıyaman.

Design: This retrospective study evaluated the data of newborn screening program in Adıyaman province between January 2015 and December 2020.

Subjects and methods: The thyroid-stimulating hormone (TSH) cut-off value in the screening program is 5.5 mIU/L and TSH values lower than 5.5 mIU/L are regarded as normal. Babies with TSH levels exceeding 5.5 mIU/L were defined as 'recalled'. TSH measurements and clinical diagnoses of the recalled babies were evaluated.

Results: TSH was <5.5 mIU/L in 62270 (90.08%) of the newborns, 5.5-20 mIU/L in 6114 (8.84%), and >20 mIU/L in 742 (1.07%). Venous T4-TSH values were normal in 673 of the 742 babies with TSH levels exceeding 20 mIU/L, while 63 babies were diagnosed with CH. Heel blood results were normal in 5880 of the 6114 babies with TSH levels of 5.5-20 mIU/L and for whom repeat heel blood was requested. TSH levels in repeat heel blood were >5.5 mIU/L in 184 babies and 93 of them were diagnosed with hypothyroidism. The recall rate among babies undergoing heel blood TSH measurement in the province of Adıyaman was 9.9%. 156 babies were started on thyroid replacement therapy with diagnoses of CH. The incidence of babies diagnosed with hypothyroidism was 1/443.

Conclusion: According to the CH screening results, the recall rate and incidence of CH in the province of Adıyaman were higher than the global general figures. Both the low TSH threshold value employed in neonatal hypothyroidism screening and the province falling within the iodine deficiency region may account for this.