Clinical approach to congenital hypothyroidism

Abstract

Congenital hypothyroidism (CH) is a preventable cause of mental retardation. The principal causes include thyroid dysgenesis and dyshormonogenesis. Central CH is rare. Due to absence of overt symptoms at birth, diagnosis is often delayed. There are some known syndromic associations with extrathyroidal anomalies. Neonatal screening programs help in early detection and categorization of cases requiring immediate treatment or close follow-up. Results of screening tests could guide further tests required for confirmation diagnosis and urgency of replacement therapy. A diagnostic protocol starting with an ultrasonography of thyroid and serum thyroglobulin levels can aid identify the probable underlying etiology and dictate the cases requiring scintigraphy or genetic tests. Early initiation of treatment with oral levothyroxine improves neurocognitive outcomes. Some cases might have transient hypothyroidism and reevaluation at 3 years of age may help in further discontinuation of treatment.