Final answer:
The most important instruction is to administer supplemental thyroid hormone daily since thyroid hormones are essential for normal growth, development, and metabolism in infants with congenital hypothyroidism. This treatment is vital for preventing cognitive impairments and growth issues associated with this condition.
Step-by-step explanation:
The most important instruction for the nurse to provide the parents of a child with congenital hypothyroidism is to administer supplemental thyroid hormone daily. Congenital hypothyroidism, or cretinism, results from underproduction of thyroid hormones (T4 and T3) due to iodine deficiency or other causes, leading to a higher secretion of thyroid stimulating hormone (TSH). The thyroid hormones are crucial for growth, development, and metabolism, particularly for brain maturation during fetal development and early childhood. Without these hormones, the child may suffer cognitive deficits and impaired growth, among other severe disorders.
Administering the thyroid hormone replacement is essential to compensate for the underproduction of the child's thyroid hormones and to prevent the adverse effects associated with hypothyroidism such as cognitive disabilities and stunted growth. The medication should be given as prescribed by the child's healthcare provider, and the dosage may need to be adjusted based on the child's thyroid hormone levels, which should be closely monitored. It's a lifelong treatment that needs careful monitoring and adjustment.
While monitoring the infant's daily intake and weekly weight, offering low sodium formula, and stimulating the infant during feedings are also important, they are secondary to ensuring the replacement of thyroid hormones which is the primary treatment for congenital hypothyroidism.