Evaluation of Thyroid Function in Children With Congenital Heart Disease

Congenital hypothyroidism is one of the most preventable causes of neurocognitive impairment because early treatment is possible in neonates. The thyroid hormone is important for normal growth and development in infancy. After introducing national screening test using capillary thyroid stimulating hormone level, the incidence of untreated congenital hypothyroidism has significantly decreased.

According to the Italian Registry of Congenital Hypothyroidism, congenital heart disease is the most frequent disease condition associated with congenital hypothyroidism.

Congenital heart disease is also reported to be a risk factor for non-autoimmune hypothyroidism in children. In addition, intravenous iodine contrast media is frequently used for diagnostic imaging and therapeutic intervention in congenital heart disease patients. Excess iodine exposed by iodine contrast media may disturb thyroid function in adult and pediatric population. However, there is no generally accepted guideline for screening thyroid dysfunction in congenital heart disease infants.

An increased prevalence of thyroid disease, particularly sub-clinical hypothyroidism, has been reported in Down Syndrome. In children with Down Syndrome, a possible concomitant sub-clinical hypothyroidism-related impairment of cardiac function or structure may worsen their clinical condition and can ultimately affect their life expectancy.