Sudden Unexpected Infant
Death (SUID) is the sudden
and unexpected death of an
infant (less than one year of
age) in which the manner and
cause of death are not
immediately obvious prior to
investigation. Based on
diagnostic criteria by the
Centers for Disease Control
and Prevention, most SUIDs
are reported as one of three
types of infant deaths: Sudden
Infant Death Syndrome
(SIDS), unknown cause, and
accidental suffocation and
strangulation in bed (ASSB).
Sudden Infant Death
Syndrome (SIDS) is the
sudden death of an infant less
than 1 year of age that cannot
be explained after a thorough
investigation is conducted,
including a complete autopsy,
examination of the death
scene, and a review of the
medical history.
Unknown Cause is the
sudden death of an infant less
than 1 year of age that cannot
be explained. Often a
thorough investigation was
not conducted and cause of
death could not be
determined.
Accidental Suffocation and
Strangulation in Bed is the
leading cause of infant injury
death. Causes of accidental
suffocation or strangulation
include:
• Suffocation by soft bedding,
such as when a pillow or
waterbed mattress covers an
infant’s nose and mouth.
• Overlay—when another
person rolls on top of or
against the infant while
sleeping.
• Wedging or entrapment—
when an infant is wedged
between two objects, such as
a mattress and wall, bed
frame, or furniture.
• Strangulation, such as when
an infant’s head and neck
become caught between crib
railings.
Brief Background Information about Sudden Unexpected
Infant Death, Safe Sleep Practices, and Breastfeeding
Saving Babies’ Lives
While there are many issues that contribute to the
unacceptably high rates of infant mortality in the United
States, there is the possibility to prevent up to 14% of infant
deaths—those categorized as Sudden Unexpected Infant
Death (SUID)—by changing the ways babies are put down to
sleep. In 2013, there were a total of 3,434 SUID related
deaths (these include 1,563 attributed to Sudden Infant Death
Syndrome (SIDS); 1052 attributed to unknown cause,
and 819 attributed to accidental suffocation and strangulation
in bed). While a small portion of deaths included in this
calculation may not be preventable due to genetic
abnormalities, arousal defects, and other non-modifiable
causes, experts agree that the adoption of safe sleep behaviors
could have a preventive impact on up to the 14% of infant
mortality data classified as sleep-related deaths.1
Why SUID rather than SIDS?
In 1969, the term Sudden Infant Death Syndrome (SIDS) was
proposed to describe a clinical entity with characteristic
findings to diagnose the sudden unexplained deaths of
infants, typically during their sleep. In 1974, federal
legislation was passed to fund research and establish
programs to provide information and counseling to families
following a SIDS death. Based on epidemiologic research
that sleep position—prone sleeping—was a significant risk
factor for SIDS and on monitoring of the success of similar
campaigns to change sleep position in other countries, the
Back To Sleep Campaign (BTS) began in 1994 as a way to
educate parents, caregivers, and health care providers about
ways to reduce the risk for SIDS. Utilizing effective
partnerships and collaboration, BTS led to a decline of SIDS
rates by more than 50%. Recognizing that placing an infant
on his/her back to sleep could significantly reduce the risk of
SIDS, both family support and advocacy organizations and
state SIDS programs expanded their efforts to disseminate
this key public health message. By 1999, however, despite
decreases in SIDS deaths, there was a leveling off, and in
some following years, a slight increase in unexpected
infant deaths overall. It became clear that many infant
deaths that might have been classified as SIDS by
coroners and medical examiners were being identified as
accidental suffocation/strangulation in bed or
undetermined, because there was more information about
the sleep situation in which the baby was found and there
were potential explanations for the death.2 It thus became
important to understand the factors that contributed to
those unsafe sleep situations to continue to decrease infant
mortality. Thus the concept of Sudden Unexpected Infant
Death (SUID) that included all of those types of deaths
came into use to aid researchers in understanding sleeprelated infant deaths.
Disparities in SIDS/SUID deaths.
SIDS and overall SUID deaths reported among Black
populations are nearly twice those of White populations.
Similarly, American Indian/Alaska Native populations
experience much higher SIDS rates than White
populations.2 Not surprisingly, given the disparities in
death rates, disparities also exist in adoption of risk
reduction behaviors. In addition, other risk factors (such as
smoking) and lack of protective factors (such as
breastfeeding) are more common among Black and
American Indian/Alaska Native families, the two
populations most impacted by SUID.3 A variety of
societal factors including poverty and the impact of racism
and discrimination contribute to these disparities.
A key challenge for the field is how to better communicate
about safe sleep and support caregivers to use safe sleep
practices in ways that are effective with all populations,
including those who have the highest rates of SUID
deaths.
What are safe sleep behaviors?
To reduce the risk of SIDS and other sleep-related infant
deaths, the American Academy of Pediatrics (AAP)
provides a set of evidence based recommendations. It
recommends that all infants be placed on their backs
Key Safe Sleep
Recommendations to
reduce the risk of SUID
based on the American
Academy of Pediatrics
Task Force on SIDS.
Always place your baby on
his or her back to sleep, for
naps and at night.
Use a firm sleep surface,
such as a mattress in a
safety-approved crib,
covered by a fitted sheet.
Room share—give your
baby his or her own sleep
area in the same room as
you or others.
Baby should not sleep in a
chair or on a couch—alone
or with others.
Keep soft objects, toys,
crib bumpers, and loose
bedding out of your baby's
sleep area.
Breastfeed.
Avoid smoke exposure
during pregnancy and after
birth.
Offer baby a dry pacifier
that is not attached to a
string for naps and at night
once breastfeeding is
established.
Keep baby from
overheating during sleep.
(known as supine position) by their caregiver for every sleep until 1 year of age. It also
recommends that infants sleep on a firm sleep surface, without loose bedding, in the same room
but not the same bed or sleep surface as parents or other persons. Bed-sharing can increase the
risk of SIDS and suffocation. Sleeping with a baby on a couch or in a chair is even more risky.
Resources to educate caregivers regarding ways to reduce the risk for SIDS and other sleeprelated causes of infant death are provided by the Safe to Sleep® campaign (previously known as
the Back to Sleep campaign). This collaborative effort was renamed and expanded in 2012 to
reflect the AAP’s broader recommendations and to address all sleep-related infant deaths.
Breastfeeding and Infant Survival and Well-being
In the United States, feeding babies with formula has become the norm, despite the many
advantages of breastfeeding. Breastfeeding provides many benefits to infants including more
balanced nutrition, protection against infections, long-term health benefits such as decreased
likelihood of developing Type 1 diabetes, asthma, or obesity and better survival during the first
year of life with decreased risk of SIDS. In addition, benefits for intellectual and emotional
development have been related to breastfeeding. As a result, the American Academy of
Pediatrics recommends that babies be exclusively breastfed for the first six months of life,
followed by continued breastfeeding as complementary foods are introduced, with continuation
of breastfeeding for 1 year or longer as mutually desired by mother and infant. In addressing
infant survival, the issue of promoting breastfeeding is crucial.
A challenge for the field is better integrating promotion of breastfeeding and safe sleep, so that
sleep practices both support breastfeeding and address safety.
Infant Caregivers Need Help
When a new baby is born, the two biggest challenges are feeding and sleeping. Successful
breastfeeding and safe sleep practices can be challenging. Even parents who know about the
benefits of safe sleep and breastfeeding sometimes choose not to adopt them. There are many
reasons for this. Sometimes parents and other infant caregivers hear conflicting information
about safe sleep and about breastfeeding. Parent/caregiver attitudes can be influenced by views
of other family and community members, personal and cultural beliefs, practical barriers, and
lack of social and economic supports from the community and workplace.
A challenge for the field is developing ways to provide individualized conversations with parents
and other infant caregivers and their support systems to help overcome barriers to safe sleep
and breastfeeding.
Making Safe Sleep Everybody’s Business
The challenges in the field to supporting caregivers and their communities to use safe sleep
practices and to promote breastfeeding are many and complex. It will take a broad coalition of
traditional safe sleep and breastfeeding proponents and many new partners to achieve success.
Because addressing sudden unexpected deaths of infants is the kind of complex issue with
multiple constituencies and programs the time is now ripe for a systems integration
approach. Bringing together organizations, community leaders, public programs, government,
and others who have a stake in keeping babies alive and developing well in a systematic way can
expand the scope of efforts and create sustainable, long-term solutions. A system can be defined
as an organized, purposeful structure that consists of a complex network of interrelated
stakeholders that continually influence one another to maintain activities to achieve the goal of
making safe infant sleep a national norm.4 The systems approach entails creating relationships,
building infrastructure to sustain the system and its activities, assuring consistent, sustainable
resources, and creating an inclusive process to achieve goals.
A challenge for the field is creating, at the state and local levels, active coalitions that create
integrated systems to address safe sleep and breastfeeding.
References
1
Centers for Disease Control and Prevention, National Center for Health Statistics. Underlying Cause of Death 1999-2013 on
CDC WONDER Online Database, released 2015. Data are from the Multiple Cause of Death Files, 1999-2013, as compiled from
data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program. Accessed at
http://wonder.cdc.gov/ucd-icd10.html on Mar 31, 2015 11:33:49 AM
2
Shapiro-Mendoza, C. K., Kimball, M., Tomashek, K. M., Anderson, R. N., & Blanding, S. (2009). US infant mortality trends
attributable to accidental suffocation and strangulation in bed from 1984 through 2004: are rates increasing?. Pediatrics, 123(2),
533-539.
3
4
U.S. Maternal and Child Health Bureau. (2013) Child Health USA 2013. Author:Rockville, MD.
WebFinance, Inc. System. In WebFinance, Inc. BusinessDictionary.com [website].
http://www.businessdictionary.com/definition/system.html#ixzz3MHThQyYt