Related Experiment Video
Updated: Jul 2, 2025
Biochemical Measurement of Neonatal Hypoxia
Published on: August 24, 2011
History of Neonatal Screening of Congenital Hypothyroidism in Portugal
Maria José Costeira1,2,3, Patrício Costa1,2, Susana Roque1,2
1Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal.
Insights
Early screening for congenital hypothyroidism (CH) in Portugal has been highly successful. The program rapidly expanded, improved detection rates through guideline updates, and became a universal practice.
Area of Science:
- Pediatrics
- Endocrinology
- Public Health
Background:
- Congenital hypothyroidism (CH) can cause developmental delays if untreated.
- Neonatal screening is crucial for early detection and intervention.
- Portugal initiated its national CH screening program in 1981.
Purpose of the Study:
- To examine the historical development and success of the CH screening program in Portugal.
- To analyze the evolution of screening strategies, coverage, and impact.
Main Methods:
- Review of annual reports and national neonatal screening laboratory data.
- Analysis of changes in screening protocols, including thyroid-stimulating hormone (TSH) cutoffs.
- Evaluation of program coverage and case identification over time.
Main Results:
- Screening coverage increased rapidly, reaching universal status within 10 years.
- Updates to guidelines and TSH cutoffs improved case detection, identifying over 200 additional cases.
- Specific protocols were developed for preterm and low-birth-weight infants.
- Screening data suggest current iodine insufficiency in the Portuguese population.
Conclusions:
- The Portuguese neonatal CH screening program is a successful public health initiative.
- The program demonstrated rapid adaptation to scientific advancements and achieved universal voluntary participation.
- Ongoing monitoring of iodine status is indicated by screening data.
Abstract:
Congenital hypothyroidism (CH) leads to growth and development delays and is preventable with early treatment. Neonatal screening for CH was initiated in Portugal in 1981. This study examines the history of CH screening in the country. Data were obtained from annual reports and from the national database of neonatal screening laboratory. The CH screening strategy primarily relies on the thyroid-stimulating hormone (TSH), followed by total thyroxine measurement as the second tier for confirmation. The TSH cutoff started at 90 mIU/L, decreasing to the actual 10 mIU/L. The coverage of the screening program has increased rapidly; although voluntary, it reached about 90% in 6 years and became universal in 10 years. Guideline and cutoff updates led to the identification of over 200 additional cases, resulting in specific retesting protocols for preterm and very-low-birth-weight babies. The actual decision tree considers CH when TSH levels are above 40 mIU/L. Data from the CH screening also provide an indication of the iodine status of the population, which is presently indicative of iodine insufficiency. The Portuguese neonatal screening for CH is a history of success. It has rapidly and continuously adapted to changes in knowledge and has become a universal voluntary practice within a few years.
