Congenital hypothyroidism (CH) is one of the most common conditions found through newborn screening, affecting roughly 1 in 2,000 to 4,000 newborns. Babies with CH are born with a thyroid gland that does not make enough thyroid hormone, which is essential for brain growth and development. Left untreated it can cause intellectual disability and growth failure, but with early treatment children develop normally, which is exactly why it is screened for.
What causes congenital hypothyroidism
Most cases are caused by a thyroid gland that did not form properly or is in the wrong place (thyroid dysgenesis). In other cases the gland is present but cannot make hormone correctly (dyshormonogenesis), which is often inherited in an autosomal recessive pattern. A smaller number of cases are temporary and related to maternal factors or iodine exposure.
How newborn screening detects it
The screen measures thyroid hormones in a few drops of blood from the heel prick, typically the level of thyroid-stimulating hormone (TSH) and sometimes thyroxine (T4). An abnormal result prompts confirmatory blood tests. Because early signs of CH are often subtle or absent, screening is the main way it is caught in time.
How congenital hypothyroidism is treated
Treatment is straightforward and highly effective: a daily dose of thyroid hormone (levothyroxine), started as early as possible, usually within the first weeks of life. Regular monitoring keeps the dose right as the baby grows. Children who start treatment early typically have normal growth and development.
How genetic screening fits in
State newborn screening does an excellent job of catching congenital hypothyroidism. Genetic screening looks at the same picture from the DNA level and, in a single test, can also assess the genes tied to more than 1,000 other clinically actionable childhood conditions, many of which are not on any state panel. Fore Genomics offers an at-home cheek-swab screen, sequenced in CLIA-certified and CAP-accredited labs, with results supported by board-certified genetic counselors. See how your state’s panel compares, see what we screen for, or start screening.
Frequently asked questions
Is congenital hypothyroidism on every state panel?
Yes. It is a core newborn screening condition included on every U.S. state panel.
Can a child with CH develop normally?
With early diagnosis and daily thyroid hormone, most children with congenital hypothyroidism grow and develop typically.
Is congenital hypothyroidism inherited?
Some forms, especially those where the gland cannot make hormone properly, are inherited. Many cases from an improperly formed gland are not clearly inherited.
Medically reviewed by Fore’s Clinical Team. This article is for general educational purposes and is not medical advice. Sources: HRSA Newborn Screening; American Academy of Pediatrics.