Population	All newborn infants*
Recommendation	Screen all newborn infants for congenital hypothyroidism
Recommendation	Grade: A
Screening tests	Two methods of screening are used most often in the United States: Primary TSH with backup T₄ Primary T₄ with backup TSH.
	Screening for congenital hypothyroidism is mandated in all 50 states and the District of Columbia.
	Physicians should become familiar with the tests used in their area and the limitations of the screening strategies employed.
Timing of screening	Infants should be tested between two and four days of age.
	Infants discharged from hospitals before 48 hours of life should be tested immediately before discharge.
	Specimens obtained in the first 24 to 48 hours of life may be falsely elevated for TSH regardless of the screening method used.
Suggestions for practice	Infants with abnormal screens should receive confirmatory testing and begin appropriate treatment with thyroid hormone replacement within two weeks after birth.
	Children with positive confirmatory testing in whom no permanent cause of congenital hypothyroidism is found should undergo a 30-day trial of reduced or discontinued thyroid hormone therapy to determine whether the hypothyroidism is permanent or transient.
	This trial of reduced or discontinued therapy should take place sometime after the child reaches three years of age.