Congenital Hypothyroidism
Congenital hypothyroidism (CH) is thyroid hormone deficiency present at birth. It affects roughly 1 in 2,000–4,000 newborns and is one of the most common preventable causes of intellectual disability.
Universal newborn screening and immediate treatment have transformed outcomes — children treated early develop normally.
Last medically reviewed: 1 November 2025
Causes
Most cases result from developmental problems: thyroid dysgenesis (absent, ectopic or underdeveloped gland — about 80%) or dyshormonogenesis (a gland that forms but cannot make hormone). A minority have central (pituitary/hypothalamic) causes.
Most cases are sporadic, though some are inherited. Maternal factors — certain medications, autoimmune thyroid disease — can rarely contribute.
Why screening matters
Without treatment, congenital hypothyroidism causes severe developmental delay, growth failure and characteristic features. Thyroid hormone is critical for brain development in the first weeks of life.
Newborn screening — a heel-prick blood spot testing TSH — is routine in most countries and allows treatment to begin within days of birth.
Treatment
Treatment is levothyroxine started as early as possible, dosed by weight and adjusted through childhood as the child grows. Most children need lifelong treatment, though a small number may recover function.
Regular monitoring of thyroid function, growth and development ensures the dose stays correct. With early, consistent treatment, the vast majority of children develop normally.
Frequently asked questions
Will my child outgrow congenital hypothyroidism?
Most children need lifelong levothyroxine, though dose requirements change with growth. A few may be re-evaluated for recovery during childhood, but permanent treatment is the norm.
Is congenital hypothyroidism inherited?
Most cases are sporadic developmental anomalies, not inherited. Some dyshormonogenesis forms are genetic — genetic counselling may be offered if there is a family history.
What if screening was missed?
If a newborn shows signs of hypothyroidism — prolonged jaundice, poor feeding, large tongue, umbilical hernia — testing should be done immediately regardless of screening status.
References & further reading
This page is based on established medical knowledge and guidelines from authoritative sources. Always consult a qualified clinician for personal medical advice.
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