ESPE Yearbook of Paediatric Endocrinology

Eur Thyroid J. 2025 Jan 31;14(1):e240327. PMID: 39812367 doi: 10.1530/ETJ-24-0327

Brief Summary: This article reviews worldwide implementation of Newborn Screening (NBS) for congenital hypothyroidism (CH), 50 years since the first pilot study in Canada in 1974. With a focus on the last decade, the authors detail current screening methods and coverage rates worldwide.

Undiagnosed congenital hypothyroidism (CH) can cause irreversible brain damage and early diagnosis and treatment can improve outcomes. NBS for CH allows early detection to facilitate early treatment. The first pilot program for CH newborn screening was started in 1974 in Quebec, Canada. However, in 2014, after 40 years, only 29.3% of newborns worldwide underwent NBS for CH, implying that 70.7% of newborns with CH are not detected and treated early. In this review, the authors identify countries with NBS programs added in the last 10 years, evaluate changes in coverage rates and identify which screening methods are used.

Of the 193 countries in the United Nations, the authors found 101 countries with established NBS programs, although 6 are covered by NBS programs in neighboring countries. Compared to 2014, 13 countries reported data showing implementation of an NBS program, with 9 of these in Central or Western Asia. An estimated 29.6% of the world’s birth population is screened for CH. This means that 70.4% of worldwide newborns are not screened for CH. There has been only minimal increase in overall screening despite addition of new programs in the last 10 years.

The authors provide an excellent world map of areas with NBS and the coverage rate, as well as one with changes compared to 2014. While coverage has improved in many countries, there were declines in Russia and Mexico and limited or no coverage in Nicaragua, India, Albania and Moldova. In Africa, only Egypt and South Africa have structured programs, although pilot programs have started in several other countries. TSH based testing is used in ~86% of programs, which is effective for detecting primary CH, but may miss central CH.

Barriers to NBS include economic constraints, lack of political or institutional support, geographic issues, lack of personnel or laboratory capacity and cultural factors. These are particular challenges in Africa and parts of Asia where the annual birth rate is high, contributing significantly to the lack of change in worldwide coverage. Improving global NBS coverage will require attention from national governments and the international global health community.