2021 ENDO-ERN/ESPE/ESE consensus: congenital hypothyroidism update

Who it applies to

Applies to neonates, infants, and children identified through newborn screening or clinical suspicion of congenital hypothyroidism, including preterm and special-risk populations.

Key recommendations

• Newborn screening programs should use TSH-based or combined TSH/T4 strategies, with awareness that screening approach affects detection of central and delayed-onset hypothyroidism.
• Confirmatory serum thyroid function tests should be obtained promptly in infants with an abnormal screening result, without waiting for screening confirmation to delay treatment when clinical suspicion is high.
• Levothyroxine treatment should be started as soon as possible after diagnosis, ideally within the first two weeks of life, using oral levothyroxine as the preferred formulation.
• Initial levothyroxine dosing should aim to normalize serum T4/free T4 rapidly, with dose individualized according to severity of hypothyroidism at diagnosis.
• Imaging (thyroid ultrasound and/or scintigraphy) can help define etiology but should not delay treatment initiation.
• In infants with mild or borderline biochemical abnormalities, a trial off treatment later in childhood may be used to distinguish permanent from transient congenital hypothyroidism.
• Preterm and low-birth-weight infants require tailored screening protocols because of higher rates of delayed TSH rise and transient hypothyroxinemia of prematurity.
• Regular monitoring of thyroid function during infancy and childhood should be frequent enough to detect over- or under-treatment, with dose adjusted to maintain age-appropriate free T4 and TSH targets.
• Genetic testing should be considered in infants with thyroid dysgenesis, dyshormonogenesis, or associated syndromic features to identify an underlying molecular cause.
• Family education and counseling about lifelong versus transient treatment needs should be part of routine care.

What is new in this edition

• Greater emphasis on individualizing screening and diagnostic pathways for preterm and special-risk neonates
• Updated guidance supporting reassessment of diagnosis later in childhood to distinguish transient from permanent disease
• Expanded discussion of genetic etiologies and when to pursue molecular testing

Practice points for students

• Do not delay starting levothyroxine while awaiting confirmatory imaging or genetic results in a screen-positive infant
• Preterm infants may have a falsely reassuring initial screening TSH due to delayed TSH surge
• Not all congenital hypothyroidism is permanent; some infants, especially with mild biochemical findings, can be safely trialed off treatment later
• Thyroid dysgenesis and dyshormonogenesis are the two broad etiologic categories, with imaging and genetics helping distinguish them

Condition

Other guidelines on this topic

• Thyroid disease: assessment and management (NG145)NICE2023Summary

Independent educational summary written by the WhiteCoat Pro editorial team with AI assistance and checked by a second AI model. It does not reproduce the guideline text, tables or figures, and it is not affiliated with or endorsed by ATA. It is not medical advice: always read the original guideline before applying it to patients.