What happens after a newborn thyroid screening alert?

What does the evidence show for congenital hypothyroidism?

• Thyroid hormone supports growth, brain development and metabolism. A newborn with low levels may appear well or have subtle findings such as reduced activity, feeding difficulty or constipation. Screening is important because visible symptoms may not provide an early warning. 1
• Newborn blood-spot screening uses a small heel sample sent to a laboratory. A screening alert is the start of a follow-up process, and repeat sampling requirements vary. Keep the requested appointments and confirm which clinician is responsible for acting on the results. 2
• The consensus guideline calls for prompt assessment after an abnormal screen, including confirmatory serum free T4 and TSH. Results require newborn age-specific interpretation. When the findings establish a need for hormone replacement, imaging should not delay starting the prescribed care. 3
• Levothyroxine supplies thyroid hormone and requires careful dosing and administration. Ask the infant’s clinician or pharmacist to demonstrate the exact formulation and method. Do not borrow another person’s tablets, switch products, mix into a full feed or improvise a dose after spitting up without advice. 4
• Blood tests and clinical follow-up are frequent early in care because the dose must fit a growing baby and the measured response. A normal result while taking medicine is not a reason to stop it. Any later reassessment of whether the condition is permanent is clinician-directed. 3

When should I call my provider about congenital hypothyroidism?

Respond promptly to a newborn thyroid screening alert and keep the requested blood-test and specialist appointments. Seek urgent care for poor feeding with marked sleepiness, a baby who is difficult to awaken or breathing difficulty. Do not wait for symptoms before arranging screening follow-up.