<![CDATA[Congenital hypothyroidism is a preventable cause of growth, developmental, and intellectual disorders when diagnosis and treatment are initiated early. However, clinical manifestations may be subtle during the early stages, resulting in delayed diagnosis when neonatal screening is not performed. This case report describes the clinical presentation, diagnosis, and management of congenital hypothyroidism diagnosed after the neonatal period. A 7-month-old female presented with developmental delay, poor weight gain, constipation, and reduced responsiveness to her environment. Physical examination revealed macroglossia and growth and developmental delays. Anthropometric measurements showed a weight of 5 kg, height of 60 cm, weight-for-age of -2.95, height-for-age of -2.61, and weight-for-height of -1.66. Laboratory evaluation revealed a free thyroxine (FT4) level of 5.15 pmol/L and thyroid-stimulating hormone (TSH) >100,000 µIU/mL, confirming congenital hypothyroidism with stunting. Treatment consisted of levothyroxine at an initial dose of 10 µg/kg/day, nutritional intervention, and physical therapy. After two months, FT4 increased to 11.06 pmol/L and TSH decreased to 12.906 µIU/mL, accompanied by increased activity, weight gain, and developmental improvement. This case emphasizes the importance of neonatal screening, early recognition of developmental abnormalities, and prompt treatment to minimize the adverse consequences of congenital hypothyroidism.]]>
