Elevated threshold for thyrotropin suppression in congenital hypothyroidism
R. M. Schultz, M. S. Glassman and M. H. MacGillivray
Five infants with congenital hypothyroidism were found to have persistently
elevated levels of serum thyrotropin (TSH) for six to 24 months after
administration of adequate doses of thyroxine. In these infants, the
hypothalamic-pituitary threshold for TSH suppression by thyroxine seems to
be unusually high. These observations suggest that serum TSH levels should
not be the sole criterion for evaluating adequacy of thyroid hormone
replacement during the initial months of therapy for congenital
hypothyroidism.
