Diagnosis and treatment of congenital hypothyroidism

Background: Congenital hypothyroidism is the most common neonatal endocrine disorder, and prompt screening and treatment initiation can prevent developmental delay and growth failure.Current Concepts: The thyroid is the first endocrine gland to develop during embryogenesis. Regulation of thyroid function requires normal development of the hypothalamic-pituitary-thyroid axis, which occurs during the embryonal and neonatal periods. Defects in any of the steps involved in development and differentiation of the gland and regulation of thyroid function lead to permanent congenital hypothyroidism. Neonatal screening test programs to detect congenital hypothyroidism, which are established in 1/3 of the countries worldwide, are cost-effective with high sensitivity and specificity. Advances in molecular testing have expanded knowledge and understanding of thyroid development and function. Prompt initiation of an accurate dose of sodium levothyroxine is recommended. Frequent follow-up, including laboratory test evaluation and dose adjustments are important to maintain thyroid hormone levels within their target ranges.Discussion and Conclusion: A well-established system of newborn screening and treatment of congenital hypothyroidism is useful for management of term infants without other risk factors for this disorder. However, increasing knowledge regarding the role of genetic causes and new criteria for screening and treatment of neonates in special conditions is emerging in clinical practice.