Neonatal hypothyroidism is decreased thyroid hormone production in a newborn. In very rare cases, no thyroid hormone is produced.
If the baby was born with the condition, it is called congenital hypothyroidism. If it develops soon after birth, it is referred to as hypothyroidism acquired in the newborn period.
Hypothyroidism in the newborn may be caused by:
Incomplete development of the thyroid is the most common defect and occurs in about 1 out of every 3,000 births. Girls are affected twice as often than boys.
Harris KB, Pass KA. Increase in congenital hypothyroidism in New York State and in the United States. Mol Genet Metab. 2007; 91(3):268-277.