Maternal Thyroxine and Congenital Hypothyroidism

Abstract

THE syndrome of cretinism, the irreversible mental retardation that occurs in infants with untreated hypothyroidism, is the best evidence that thyroid hormone is required for normal human development. Nonetheless, most newborn infants with congenital hypothyroidism are asymptomatic and must be identified by biochemical screening. Furthermore, the great majority of the infants treated after having been identified by such screening programs have normal intellectual development. How can the apparent normality of hypothyroid infants at birth be reconciled with their profound abnormality if not treated very soon after birth? The report of Vulsma et al. in this issue of the Journal demonstrates . . .