Safe Sleep and Sudden Infant Death Syndrome (SIDS)

Causes of infant death that are linked to how or where a baby sleeps or slept are called “sleep-related.” These deaths happen by accident when a baby cannot get enough air. This is usually when the baby:

  • gets trapped between two objects, such as a mattress and a wall, and cannot breathe (entrapment).


  • has something pressing on or wrapped around their neck, blocking the baby’s airway (suffocation). 

A death from these causes is called a Sudden Unexpected Infant Death (SUID). SUID is when a baby less than one year old dies suddenly, and the cause was not clear before the death was investigated. These deaths often happen during sleep or in the baby’s sleep area.

Sudden Infant Death Syndrome (SIDS) is one type of SUIDSIDS is when a baby less than one year old dies suddenly, but the cause of death cannot be explained even after it is fully investigated. This means a cause is not found even after a complete autopsy, a study of the death scene, and a review of the baby’s clinical history.

In Santa Clara County, most infant deaths are caused by unsafe sleep areas and are not found to be SIDS events. 

Infant deaths due to unsafe sleeping situations can be prevented. Every parent and caregiver can help protect their baby if they follow these safe sleeping guidelines:

  • Babies need to sleep alone in a crib or bassinet with a firm mattress and a well-fitted sheet.
  • Babies should be put to sleep on their backs during naps or at nighttime.
  • Babies should not be placed on their sides to sleep because they may accidentally roll onto their stomachs and suffocate (they may die because they cannot breathe).
  • Babies should not sleep on adult beds, chairs, sofas, waterbeds, cushions, or nursing pillows. 


Safe sleep guide


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Safe sleep recommendations 

Remember the ABCs

Alone: Always make sure the baby is alone in the crib. No toys, pillows, crib bumpers, or any other soft objects should be in the sleeping area.

Back: The baby should always be placed on their back.

Crib: The baby should be placed in a safety-approved crib that has a firm mattress covered by a tightly fitted sheet. 

Safe sleeping guidelines

  • Always place the baby on their back when putting the baby to sleep.

  • Use a safe sleeping surface. A great example is a safety-approved crib that has a firm mattress covered by a tightly fitted sheet.

  • Remove all soft objects, crib bumpers, toys, and any loose bedding from the baby’s sleeping area.

  • Do not smoke or let anyone else smoke around your baby or the baby’s sleeping area.

    • The smoke can be trapped in the sheets, toys, crib bumpers, and clothes of the baby, which has harmful effects on its health. 

    • Thirdhand smoke clings to clothes, furniture, drapes, walls, bedding, carpets, dust, vehicles, and other surfaces long after smoking has stopped. The residue from thirdhand smoke builds up on surfaces over time.

  • Share a room, not a bed.

    • Room sharing is when you and the infant sleep in the same room but do not share the same sleeping surface. 

    • Bed sharing is when you and the infant share the same sleeping surface. 

      • An example of bed-sharing is sleeping in the same bed with the baby. This is also called co-sleeping.


  • Avoid putting your baby to sleep on sofas, cushions, chairs, and waterbeds.

    • Sleeping with the baby on a sofa or chair causes the most suffocation deaths (when the baby stops breathing) in Santa Clara County, according to the Santa Clara County Child Death Review Study.

  • Room temperature

    • If the room temperature is comfortable for you, it will also be for the infant.

How to use a blanket while practicing safe sleep

  1. Place your infant so that the baby's feet are pointing towards the end of the crib. 
  2. Make sure that you are using a thin blanket, not a thick one.
  3. The blanket should not reach higher than the baby’s chest.
  4. Do not forget to tuck the sides and end of the blanket underneath the mattress! 

Resources for safe sleep  

  • SIDS: Me and My Family: The California Department of Public Health’s webpage has more information about SIDS and a link to “Safe Sleep Environments for Infants.” 
  • About SIDS and Safe Infant Sleep: The U.S. Department of Health and Human Services' Safe to Sleep campaign website has detailed information and facts about SIDS and safe sleep.
  • Safe to Sleep Campaign Materials: The Safe to Sleep campaign has information about safe infant sleep that you can print out and share. There are messages for different ethnic groups and relationships, including grandparents.
  • How to Keep Your Sleeping Baby Safe: AAP Policy Explained: The American Academy of Pediatrics' webpage has recommendations for safe sleep.

Videos on safe sleep 


Safe to Sleep webpage: “About SIDS/Safe Infant Sleep"

Centers for Disease Control and Prevention (CDC) SIDS webpage

AAP Task Force on Sudden Infant Death Syndrome webpage

National Institute of Health’s Safe to Sleep campaign webpage

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