Does breast-feeding protect the hypothyroid infant whose condition is diagnosed by newborn screening?
J. F. Rovet
Department of Psychology, Hospital for Sick Children, Toronto, Ontario, Canada.
Neuropsychological abilities at 1, 3, 5, and 6 years of age were compared
in 107 children with congenital hypothyroidism identified by newborn
screening who had been either breast-fed or formula fed during infancy. The
thyroxine level was significantly higher in breast-fed children than
formula-fed children at 1 and 2 months of age, but the level was not higher
later during the first year of life. Controlling for parent IQ,
socioeconomic status, and dose level, no differences in overall
neuropsychological functioning were observed. Children with ectopic glands
showed a significant advantage with breast-feeding on several tasks at 3
years of age. These results signify that thyroxine levels in infancy from
breast-feeding are not necessarily reflected in improved intellectual
functioning later in childhood.
