Thyroid dysfunctions in children detected in mass screening for congenital hypothyroidism

Abstract

Congenital hypothyroidism (CH) affects approximately 1:3000-1:4000 infants. To determine the prevalence of CH and isolated hyperthyrotropinemia (IHT) in newborns selected in mass screening for CH. Mass screening of 233,120 neonates born in southeastern Poland was carried out and CH-suspected children were identified. Serum thyroid-stimulating hormone and free thyroxine levels were determined during first confirmation and diagnosis re-evaluation in 118 and 34 children, respectively. Additionally, the patients were subjected to thyroid ultrasonography (n=53) and/or scintiscan (n=28). Out of 118 children, first confirmation indicated CH in 58 neonates and IHT in 4 neonates. Out of these, 34 were re-evaluated with regard to diagnosis. A final diagnosis of permanent CH was reported in 34 children with thyroid dysgenesis (n=27) or dyshormonogenesis (n=7), transient CH affected 15 children, and permanent IHT was diagnosed in 6 children. CH prevalence was 1:4570 (permanent 1:6475, transient 1:38,853) and permanent IHT 1:38,853. The prevalence of CH and IHT corresponds to the prevalence of the condition in iodine-sufficient and borderline iodine-deficient areas.