It is often difficult to determine the cause of death of a child who succumbed to SUDC. The deaths are “rarely witnessed and postmortem examinations are unrevealing ... Death mechanisms and causes of death remain unknown.”
SUDC is different from sudden infant death syndrome (SIDS). SUDC is not a diagnosis but a cause of death used for someone between 12 months and 18 years old who has died from unknown circumstances. SIDS is much more common, with a death rate of 38.7 per 100,000 live births; SUDC has a death rate of 1 to 1.4 per 100,000 live births (2023).
In 2021, sudden unexplained childhood death (SUDC) killed 2,900 children under the age of 4 in the United States. According to the U.S. Centers for Disease Control and Prevention (CDC), SUDC is the fifth leading cause of death for children between the ages of 1 and 4 years old.