Sudden Unexpected Infant Deaths in Italy, 1996-2023: An Epidemiological Update

Abstract Purpose To provide an updated epidemiological profile of Sudden Infant Death Syndrome (SIDS) and Sudden Unexpected Death in Infancy (SUDI) in Italy from 1996 to 2023. Methods Data on causes of death and live births from 1996 to 2023 were obtained from the databases of the Italian National Institute of Statistics (ISTAT). SUDI and SIDS cases were identified using ICD-9 and ICD-10 codes. The analyses included descriptive statistics, non-linear sigmoidal trend models, linear regression, the Mann-Kendall test, and chi-square tests to assess geographic differences. Results Between 1996 and 2023, Italy's infant mortality dropped 54.8%, with perinatal conditions, congenital anomalies, and SUDI accounting for 84.8% of all infant deaths. A total of 1,585 SUDI cases were recorded, of which 40% were classified as SIDS. Although SIDS rates declined over time, the reduction in overall SUDI rates was less pronounced. SUDI rates were significantly higher in Southern Italy (7.6 per 100,000) than in Northern (5.3) and Central Italy (3.2). The relative contribution of SUDI to overall infant mortality nearly doubled, increasing from 2.8% in 1996 to a peak of 5.5% in 2022. Between 2016 and 2023, only 8.8% of SIDS cases included a recorded autopsy (ICD-10: R95.0). Conclusion Despite the overall decline in mortality, significant temporal changes in the distribution of SIDS and other causes of neonatal death persist. The findings underscore the urgent need to enhance post-mortem investigations and strengthen surveillance systems to improve our understanding of the pathophysiology of SIDS and SUDI.