Unsafe sleep factors were present in at least 73% of sudden infant deaths

Sudden unexpected infant death (SUID) is investigated through the SUID and
Sudden Death in the Young Case Registry, which collects
circumstances-at-death data — what was actually happening around the
baby. That information complements vital statistics and is, in the registry's
own words, critical to prevention.

A death certificate records that an infant died. The registry records where
they were sleeping, on what, with whom.

What five years of data shows

Analysis of 2020–2024 case registry data found the sociodemographic
characteristics and risk factors were similar to previous reports:

Unsafe sleep factors were identified in at least 73% of cases.

Two of those figures push against the intuition. Three quarters of these
babies were born at full term — this is not primarily a complication of
prematurity. And the risk is concentrated in the first three months, which
is exactly the window when parents are most exhausted and most likely to fall
asleep holding a baby or bring one into an adult bed.

The Medicaid figure is not a cause. It is a marker of the households the
prevention message has to reach.

The limit of the data

**Almost all SUIDs had an autopsy and a death investigation — but
completeness varied.**

That caveat sits underneath everything above. "Unsafe sleep factors identified
in ≥73% of cases" is a floor rather than a rate: it counts the cases where an
investigation found and recorded them. Where the investigation was less
complete, the factors may have been present and unrecorded.

Which makes the consistency of these findings across successive reports the
strongest thing about them: the same picture keeps appearing, through
investigations of varying thoroughness, over years.

*Source: Erck Lambert AB, Parks SE, Cottengim C, et al. Characteristics of
Sudden Unexpected Infant Deaths — United States, 2020–2024. MMWR, Centers for
Disease Control and Prevention.*