Congenital hypothyroidism (CH), the most common pediatric endocrine disorder with an estimated prevalence of 1:2,000 to 1:4,000, is an under-recognized problem in countries without routine newborn screening (NBS) programs. Thyroid dysgenesis (TD) is the most common cause of primary CH accounting for approximately 85% of all cases; most of the remaining patients have dyshormonogenesis. Transient CH and CH with eutopic gland, are increasingly being identified after introduction of routine NBS.
The clinical features of CH are often subtle resulting in delayed diagnosis and eventually poor intellectual outcome. In developed countries, detection by NBS and early initiation of treatment has largely eliminated the intellectual disability caused by this disorder. The lower screening thyroid stimulating hormone (TSH) cutoff and changes in birth demographics in some countries have been associated…
