July/August 2016
15
feature
About 3,500 infants in the United States
die suddenly
and unexpectedly each year. These deaths are often referred to as
sudden unexpected infant deaths (SUID). Although the cause of many
of these deaths can’t be explained, most occur while the infant is
sleeping in an unsafe sleeping environment. Researchers can’t be
sure how often deaths happen because of accidental suffocation
from soft bedding or overlay (another person rolling on top of or
against the infant while sleeping). Often, no one witnesses these
deaths, and there are no tests to tell sudden infant death syndrome
(SIDS) apart from suffocation.
1
SIDS and SUID
In most cases of sudden infant death, an autopsy fails to provide
an adequate cause of death, and an investigation of the environ-
ment in which death occurred becomes an important source of
information. The King County Medical Examiner’s Office (KCMEO)
has been conducting careful scene investigations on every sudden
infant death for over two decades. From observations made in
scene investigations has come a growing recognition of the condi-
tions associated with sudden infant deaths. The terminology used
for death certification has evolved in parallel.
In King County, the label “Sudden Infant Death Syndrome” (SIDS) is
used to certify the sudden, unexpected death of a previously healthy
infant in which scene investigation, complete autopsy with ancillary
studies, and review of the case history fail to reveal a specific cause
of death. In addition, the scene investigation provides no evidence
for asphyxia, for example, by overlying or suffocation by bedding
or other items in the infant’s immediate sleeping environment. With
no evidence to indicate otherwise, the manner of death in SIDS is
certified “Natural.” Along with the cause and manner, the death
certificate may list risk factors that are not considered causative or
contributory, for example, “Prone sleeping on soft bedding.”
The alternate label, “Sudden Unexplained Infant Death” (SUID),
is used to certify the death of a previously healthy infant similar to
SIDS in which scene investigation, autopsy with ancillary studies, and
review of the case history fail to reveal a specific cause of death.
Unlike SIDS, in this category there is the real possibility of asphyxia,
but it cannot be proven to a level of consensus among the assem-
bled five KCMEO forensic pathologists. The typical circumstance in
SUID is an infant sharing a common surface with one or more bed
partners. The manner of death certified in SUID is “Undetermined,”
and along with the cause and manner, the death certificate reports
potentially contributing conditions, for example, “Bed sharing with
two adults in a single bed,” and explains the reason for the unde-
termined manner in a statement, “Unable to determine if external
conditions contributed to death.”
It is important to understand that certification of sudden infant deaths
is not standardized and there are wide variations depending on
jurisdiction. The approach outlined here is the practice of KCMEO.
Other counties in Washington may certify all sudden unexplained
infant deaths as simply, “Unknown cause” and “Undetermined
manner,” while KCMEO prefers to upgrade the older SIDS termi-
nology by including the newer SUID category as a way to distin-
guish what appear to be perfectly natural deaths from those in
which external conditions may have been contributory.
It is also worth understanding that the cause of most sudden infant
deaths is obscure and that more work needs to be done to under-
stand why infants die and how to protect them. Thus, it is impor-
tant that all sudden infant deaths are investigated carefully, starting
with a careful scene investigation and review of the infant’s history,
followed by a complete autopsy. These measures are critical, not only
to exclude injuries and natural diseases in the deceased infants, but
also to gain information that could keep other babies from dying.
1. CDC website 2016
Manner of Death:
Natural
Cause of Death:
Sudden Infant Death Syndrome
• Sleeping alone with no concerns for asphyxia
• Bedsharing with single adult and
no concerns for asphyxia
• Risk factors listed in “Other Significant Conditions”
Manner of Death:
Undetermined
Cause of Death:
Sudden Unexplained Infant Death
• Possibility for asphyxia but cannot be proven
• Bedsharing with more than one adult
• Sleeping on couch or potentially
hazardous sleeping surface
• The phrase “Cannot determine if external factors
contributed to death” is listed in “How injury occurred”
Cause of Death:
Undetermined Cause
• Asphyxia very likely but cannot be
proven to a level of consensus
• A phrase describing how asphyxia may have
occurred is listed in “How injury occurred,”
for example: “Compressional asphyxia during
bedsharing with adult cannot be excluded”
Manner of Death:
Accident
Cause of Death:
Asphyxia (qualified by type)
• Asphyxia is reasonably proven to a level of consensus
• There is no indication of intent or
“unreasonable” neglect
• The mechanism of asphyxia is described
in “How injury occurred”
