Sudden infant death syndrome

Trials started per year, stacked by phase (darker = later phase). Source: ClinicalTrials.gov via Clin2, which tracks studies recruiting in recent years — early years undercount.

SIDS is largely preventable. Most typical cases are tied to sleep environment, and safe sleep practices—back sleeping, firm surface, no soft bedding—have cut rates by more than half in many countries since the Back to Sleep campaign began. Deaths have been falling steadily for decades, though the decline has slowed in recent years. Not every case can be avoided: rare genetic or metabolic causes remain. Research is active, with 14 trials started in the last five years and three in late-stage testing, focusing on understanding underlying vulnerabilities beyond sleep environment.

Can SIDS be completely prevented?

No, not all cases. Most are preventable with safe sleep practices, but a small proportion stem from genetic or metabolic conditions that cannot yet be predicted or avoided.

Why have SIDS rates fallen over time?

Public health campaigns promoting back sleeping and safer sleep environments have been the main driver. In many countries, rates dropped by more than half after these efforts began.

Is research continuing?

Yes. More than a dozen trials are currently active, including three in phase 3. Research aims to identify risk markers and better understand causes beyond sleep environment.

What is the current trend?

SIDS deaths have declined steadily since the 1990s, but the pace of decline has slowed in recent years, meaning the remaining cases are a persistent challenge.

Are there genetic causes?

A small fraction of SIDS cases are linked to genetic or metabolic abnormalities. These are not related to sleep environment and are not preventable by current safe sleep measures.