Newborn babies who are unable to make enough thyroid hormone have congenital hypothyroidism. Thyroid hormone is essential for brain development. If the condition is not found or left untreated, it can result in irreversible neurological problems and poor growth. However, if this hormone deficiency is treated within 2-3 weeks after birth, permanent brain damage can be avoided.
In Belgium, about 1 in every 2,000 to 3,000 newborns has congenital hypothyroidism, which is about 30 to 40 babies per year. It is twice as common in girls as in boys.
In most cases, the condition is permanent, and the child will need lifelong treatment.