It is unclear how often these events occur.

BRUE is NOT the same as sudden infant death syndrome (SIDS). It is also NOT the same as older terms such as "near-miss SIDS" or "aborted crib deaths," which are no longer used.

Events that involve a change in an infant's breathing, color, muscle tone, or behavior may be caused by an underlying medical problem. But these events would then NOT be considered a BRUE. Some of the causes for events that are not a BRUE include:

Reflux after eating

Severe infections (such as bronchiolitis, whooping cough)

Birth defects that involve the face, throat, or neck

Birth defects of the heart or lungs

Allergic reactions

A brain, nerve, or muscle disorder

Child abuse

Certain uncommon genetic disorders

A specific cause of the event is found about half the time. In healthy children who only have one event, the cause is rarely identified.

The main risk factors for BRUE are:

A prior episode when the child stopped breathing, turned pale, or had blue coloring

Feeding problems

Recent head cold or bronchitis

Age younger than 10 weeks

Low birth weight, being born early, or secondhand smoke exposure also may be risk factors.