Improvements in screening test, diagnosis, and outcomes of children with congenital hypothyroidism: lessons learned from 50 years of newborn screening

Congenital hypothyroidism (CH) may result from a developmental or functional defect of the thyroid gland (primary CH), or to hypothalamic-pituitary axis dysfunction (central CH), or more rarely from abnormalities in the action, transport, or metabolism of thyroid hormones. In the absence of prompt initiation of replacement therapy during the neonatal period, CH can lead to profound impairment in growth and neuropsychomotor development. Since signs of CH early in life can be subtle and difficult to recognize, early detection and prompt treatment goals have been achieved by newborn screening (NBS), which was started fifty years ago.

A narrative review was conducted to identify studies describing how the evolution of NBS for CH has contributed to improve diagnostic accuracy and outcomes of affected children.

From its start, the main objective of NBS for CH has been the eradication of intellectual disability resulting from severe CH. However, over decades it has become clear that CH covers a spectrum of phenotypes, including mild, moderate, and severe forms of hypothyroidism. In addition, numerous outcome studies have confirmed that early CH detection by NBS followed by timely replacement therapy effectively prevents brain damage, underscoring the success and importance of this screening program.

The improvement of NBS and advances in the management of CH have dramatically enhanced patient outcomes through increasingly personalized care from birth to adulthood. Although overall outcomes are generally favorable, ongoing monitoring of treatment adequacy and patient adherence remains essential.