What levothyroxine dose is used in congenital hypothyroidism?

Starting dose 10-15 mcg/kg/day; start as soon as possible after diagnosis (within 2 weeks of life); crush and mix with small amount of breast milk/formula; target fT4 in upper half of normal range (15-28 pmol/L) and TSH <5 mU/L within 2 weeks.

What TSH target is recommended in treated CH?

TSH target <5 mU/L (ideally 0.5-4.0 mU/L); fT4 in upper half of normal for age; over-treatment (TSH <0.1) is associated with behavioral issues and advanced bone age; under-treatment causes intellectual disability.

How often should thyroid function be monitored in CH?

Monitor TSH + fT4 every 2-4 weeks until target achieved; monthly for first 6 months; every 2-3 months 6-12 months; every 3-4 months 1-3 years; then annually; increase monitoring during illness or dose change.

What factors affect levothyroxine absorption in infants?

Soy formula reduces LT4 absorption 25-40%; calcium-fortified formulas similarly reduce absorption; antacids, cholestyramine, iron reduce absorption; administer LT4 30-60 min before feeding or crushed and given separately from problematic feeds.

When does congenital hypothyroidism resolve?

Transient CH (25% of cases): TSH normalizes by age 3 when dose is gradually reduced; permanent CH requires lifelong replacement; trial off treatment at age 3 years by reducing dose by 30% for 4 weeks then checking TSH off medication.

Congenital Hypothyroidism Levothyroxine Dose Calculator

Calculates initial and maintenance levothyroxine dosing for congenital hypothyroidism by age/weight (10-15 mcg/kg/day neonate), with TSH and fT4 targets to optimize neurodevelopmental outcomes.

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Congenital Hypothyroidism Levothyroxine Dose Calculator

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Frequently Asked Questions

What levothyroxine dose is used in congenital hypothyroidism?

What TSH target is recommended in treated CH?

How often should thyroid function be monitored in CH?

What factors affect levothyroxine absorption in infants?

When does congenital hypothyroidism resolve?