A nurse is caring for a school-age client who was prescribed thyroid hormone replacement therapy for hypothyroidism. The nurse should educate the caregivers about the importance of the medication in preventing which priority complication?

A. Delayed bone growth: Hypothyroidism can affect linear growth in school-age children, but the most urgent concern is cognitive development, as thyroid hormone is critical for brain maturation and neurological function. B. Hypoglycemia: Hypoglycemia is not a direct complication of hypothyroidism. Thyroid hormone primarily affects metabolism, growth, and neurological development rather than blood glucose regulation. C. Precocious puberty: Hypothyroidism is more commonly associated with delayed puberty rather than precocious puberty, making this a less relevant concern in medication education. D. Cognitive impairment: Thyroid hormone replacement is essential to prevent intellectual delays and cognitive deficits. Inadequate thyroid hormone during critical developmental periods can lead to long-term impairment in learning, memory, and overall neurological function.