Definition

Sudden infant death syndrome (SIDS) refers to the unexpected, unexplained death of a child less than one year old. SIDS is rare during the first month of life. It peaks at 2 to 4 months of age, then gradually decreases.

Causes

Experts do not know the exact cause of SIDS. Many theories exist. Potential causes include:

• Abnormalities in a section of the brain that controls breathing during sleep and waking
• Abnormalities in the control of heart rhythm
• Changes in how serotonin, a neurotransmitter, functions in the brain
• Changes in some components of the immune system
• Inadequate arousal response to breathing obstruction or asphyxia (a lack of oxygen or excess carbon dioxide in the body caused by interruption of breathing; may cause unconsciousness)

Brainstem

Area of the brain involved in regulation of breathing.

© 2011 Nucleus Medical Media, Inc.

Risk Factors

Risk factors that increase the chance of SIDS include:

• Infant's age: less than 6 months old
• Low birth weight
• Fetal delayed growth
• History of SIDS death in a sibling
• History of an acute life-threatening event
• Previous incident of unexplained severe apnea (when breathing is repeatedly interrupted) requiring resuscitation
• Sleeping on the stomach or side rather than back
• Other risk factors are more general and include:
  • Mother's age: younger than 20 during first pregnancy
  • Poverty
  • Black, Native American, and Alaskan Native families
  • Sex: male
  • Smoking during pregnancy or in a house where the baby is sleeping
  • Alcohol, opiate, or cocaine use during pregnancy
  • History of anemia or a urinary tract infection while pregnant
  • No or late prenatal care
  • Premature birth
  • Recent infection and/or fever
  • Cold weather in late fall or winter
  • Overheating
  • Low socioeconomic status or low level of education
  • No pacifier use at bed time

Symptoms

A baby that dies of SIDS typically appears healthy. He may have had a cold or gastrointestinal infection in the two weeks prior to death. There usually are no warning signs that a baby is about to die of SIDS.

Diagnosis

All possible illnesses and causes of death must be ruled out before a diagnosis of SIDS is made. A complete investigation will take place including:

• Autopsy
• Assessment of the death scene
• Review of the baby's and family's medical histories

Treatment

Emergency medical personnel should be called as soon as the infant is discovered not breathing. Infant CPR should be started immediately. Seek immediate medical care even if the baby starts breathing again. The cause of the incident should be fully evaluated. Families may need grief counseling after the death. Some parents find support groups helpful.

Prevention

There is no way to predict which infants will die of SIDS. Several actions may help you lower your child's risk of SIDS:

• During pregnancy:
  • Get prenatal care early and regularly.
  • Do not smoke, drink alcohol, or use drugs while pregnant.
• After birth:
  • Until your baby turns one year old, put him to sleep on his back. Do not allow a young baby to sleep on his stomach or side. Ask your doctor for more information about positioning your baby for sleep.
  • Other factors that may help reduce SIDS risk include:
    • Provide a firm crib mattress.
    • Breastfeed your baby.
    • Do not place blankets, a comforter, pillow, or sheepskin under your baby.
    • Do not let your baby sleep on a waterbed.
    • Remove soft, stuffed toys and loose bedding from the sleep area.
    • Do not cover your baby's head or face.
    • Have your baby sleep in the same room as you do, but do not share your bed.
    • Keep the bedroom room at a comfortable temperature (68°F-72°F).
    • Avoid overheating. Do not overdress your baby.
    • Give your baby a pacifier during nap time and bedtime.
    • While your baby is awake, place him on his stomach so that he can move his body.
    • If you smoke, do not smoke in the house or around your baby. Ask your doctor about ways you can quit.
    • Be sure that your baby gets routine medical care, including the recommended vaccines.
    • Do not use cardiorespiratory monitors or other commercial devices that claim to reduce the risk of SIDS. There is no evidence that these devices are useful.
    • Learn infant CPR.

  Make sure anyone else caring for your child is also aware of these recommendations, especially that the baby should be placed on his back for sleeping.