ESPE Yearbook of Paediatric Endocrinology

Brief Summary: Countries differ in their approaches to newborn screening (NBS) for congenital adrenal hyperplasia (CAH), a group of genetic disorders affecting adrenal steroidogenesis. This survey describes the protocols, approaches, and outcomes of CAH screening across different countries.

Members of the International Society for Neonatal Screening were invited to complete a questionnaire in 2021. Members representing 23 screening programs from Europe, Southeast Asia, Australasia, and South America responded to the survey. Of these 21 programs had current active CAH screening and 2 programs were planning to start CAH NBS in the next year. Data on the screening process and outcomes for 2020 were collected.

The study found significant differences in how countries conduct NBS for CAH, in the timing, testing methods, and interpretation of results. Most programs perform sampling between 48 and 72 hours after birth, but other countries allow earlier or later collection. Laboratory techniques vary from a single national laboratory, to multiple labs using standardized protocols, to differing lab protocols within the same country. More than half of programs use a single-tier testing protocol measuring 17OHP by immunoassay. Nine screening programs have introduced or planned to use second-tier testing to reduce false positives. Many programs adjust the 17OHP cutoff values based on gestational age or birth weight to improve screening accuracy. However, the methods for determining these cutoffs are not standardized, leading to further variability. 19 programs provided data on the numbers of– this ranged from 4,500–700,000 infants per year (median 46,000 per year). Participation rates were high ≥99% in the programs reporting this data.

This study highlights the challenges in implementing effective CAH screening programs, including the balance between reducing false positives and ensuring early detection. It highlights the large variation in methods used, and indicates potential for standardization across national programs to optimize the early detection of CAH and improve outcomes for affected infants.

References: 1. Clayton PE, Miller WL, Oberfield SE, Ritzén EM, Sippell WG, Speiser PW, et al. Consensus statement on 21-hydroxylase deficiency from the European Society for Paediatric Endocrinology and the Lawson Wilkins Pediatric Endocrine Society. Horm Res. 2002;58(4): 188–95.2. Pang S, Shook MK. Current status of neonatal screening for congenital adrenal hyperplasia. Curr Opin Pediatr. 1997;9(4):419–23