A 6-week-old female infant exhibits dry scaly skin and a protruding tongue after having trouble breast-feeding. A diagnosis of congenital hypothyroidism is made. The mother asks the nurse why the child was not diagnosed with this condition at birth. Which of the following would be the nurse’s best response
A. "We had the results of the newborn screen, but you did not bring the baby in for the 2-week checkup. "
B. "We could not reach you at home to give you the results of tests taken at birth. "
C. "Your baby had little need for thyroid hormone until she was 1 month old. "
D. "Newborns generally receive enough thyroid hormone from the mother to get by the first few weeks. "
参考答案：D
解析：With congenital hypothyroidism, failure of normal development occurs during the embryonic period or when an inborn error of metabolism prevents the normal synthesis of thyroxine. Although the condition is present at birth, maternal thyroxine can pass through the placenta to the fetus, supplying the fetus and neonate sufficiently. Thus, in most neonates, the signs of hypothyroidism are commonly masked at birth.