What are the recommended guidelines for screening and managing congenital hypothyroidism in newborns?

Screening for congenital hypothyroidism in newborns is typically performed through newborn bloodspot screening, which is standard practice in the UK to enable early detection and treatment, although specific screening details are not explicitly outlined in the provided guideline excerpt.

Management of congenital hypothyroidism involves initiating levothyroxine treatment promptly to normalise thyroid hormone levels and support normal growth and neurodevelopment.

For children under 2 years of age diagnosed with primary hypothyroidism, levothyroxine treatment is recommended, with dosing and monitoring tailored to age and clinical response.

Monitoring during treatment for children aged between 28 days and 2 years includes measuring free thyroxine (FT4) and thyroid-stimulating hormone (TSH) every 4 to 8 weeks until TSH stabilises (defined as 2 similar measurements within the reference range 2 months apart), then every 2 to 3 months during the first year of life, and every 3 to 4 months during the second year of life.

Once stable, monitoring frequency may be reduced, but ongoing follow-up is essential to ensure optimal thyroid function and development.

Levothyroxine is the first-line treatment; natural thyroid extract and liothyronine are not recommended due to lack of evidence and safety concerns.

Screening and management should be coordinated with paediatric and endocrine specialists to ensure appropriate dosing and follow-up.

These recommendations align with the NICE guideline NG145 on thyroid disease: assessment and management.