Advancements and insights into newborn screening with tandem mass spectrometry in China: a comprehensive descriptive analysis (2017–2021)

Background Tandem mass spectrometry (MS/MS) has been progressively integrated into newborn screening (NBS) in China over the past decades. However, variations exist in screening strategies, coverage and support systems across different regions. This study aims to investigate the current status of MS/MS-based NBS across China, providing insights into progress and future challenges. Methods This retrospective investigation included 42 634 198 newborns screened at 267 NBS centres across 28 provinces in China between 2017 and 2021. These centres were divided into Eastern, Central and Western regions based on geographical location and economic development level. Data analysis focuses on screening rate, suspected positive rate, incidence and diagnostic efficiency of MS/MS-based NBS across these regions. Results Over the 5-year study period, the nationwide MS/MS-based screening rate increased consistently from 36.93% in 2017 to 49.93% in 2021, with the prominent trend in the Central region. The suspected positive rates of amino acid metabolism disorders, organic acid metabolism disorders and fatty acid oxidation disorders showed a notable upward trend. In 2021, the nationwide incidences of amino acid metabolism disorders, organic acid metabolism disorders and fatty acid oxidation disorders were 15.34, 12.59 and 13.18 per 100 000 live births, respectively. Despite challenges, the diagnostic time for organic acid metabolism disorders in the Western region significantly improved, and similar ascending trends were observed for fatty acid oxidation disorders in most regions. Conclusion Our findings highlight the remarkable progress of MS/MS in China’s NBS and its indispensable role as the primary method. Continued advancement will be key to improving health outcomes and safeguarding the well-being of newborns nationwide.