Sudden Infant Death Syndrome (SIDS)

Last Updated February 2021 | This article was created by editorial staff and reviewed by Peter Rippey, MD, CAQSM

What is sudden infant death syndrome (SIDS)?

Sudden infant death syndrome (SIDS) is the unexplained reason a baby under the age of 1 dies while sleeping.

When a baby dies unexpectedly, the police and a medical examiner investigate the death. They look at where the death occurred, do an autopsy on the baby, and look at the baby’s health history.

What are the symptoms of sudden infant death syndrome (SIDS)?

Part of the frustration of SIDS is that there are no warning signs or symptoms. All a parent or caregiver can do is take preventive steps to reduce the chance of SIDS (see the “prevention” section in this article).

What causes sudden infant death syndrome (SIDS)?

SIDS is believed to be related to certain sleeping hazards that can cause the baby to stop breathing. These include:

  • Soft bedding covering the baby’s face
  • A baby getting wedged or trapped between a mattress and something else in the bed or crib
  • A baby lying on their side or stomach and unable to roll over or lift their head
  • An adult accidentally rolling on top of the baby while sharing a bed

Babies born with defects in the part of their brain that controls breathing and waking from sleep are more likely to die of SIDS. Respiratory infections may also increase a baby’s likeliness of dying from SIDS.

According to the Safe to Sleep® Campaign, SIDS isn’t contagious. It’s not caused by choking or vomiting, and it isn’t tied to child abuse or the lack of immunizations. It’s not the same as, or caused by, suffocation.

How is sudden infant death syndrome (SIDS) diagnosed?

An infant is diagnosed as having died of SIDS after all other causes have been excluded. Professionals will try to determine the cause of death and conduct interviews with parents or caregivers. They also will check the baby’s medical records. They will examine the spot where the baby died, usually a crib or a bed. SIDS is listed as a cause of death after an autopsy.

Can sudden infant death syndrome (SIDS) be prevented or avoided?

There is no sure way to prevent SIDS, but there are ways to reduce your baby’s risks. If you are a parent or caregiver, there are ways to keep your baby’s sleep space safe:

  • Remove all loose bedding, such as crib bumpers, blankets, pillows, stuffed animals, and toys. These items can cause the baby to choke or stop breathing. They also can strangle the baby.
  • Make sure you have the most recent, baby-friendly crib. It should be designed to keep your baby from falling between the mattress and the side of the crib. It’s also important to make sure your baby can’t get their head stuck in the bars of the crib. While an older, used crib may be more affordable, look for a newer one to match your budget and keep your baby safe. Choose a firm crib mattress over a softer one.
  • Don’t allow your baby to sleep with you, another adult, or another child. You may forget to return a fussy baby to its crib and accidentally roll on top of it. This causes the baby to stop breathing.
  • Place your baby on their back (not their tummy or side) for naps and at night. A baby’s neck and muscles aren’t fully developed that would allow them to lift their head or roll over. When the baby is “stuck” on their tummy, they can’t lift their head to breathe.
  • Have your baby sleep in your room but on a separate sleeping surface for at least 6 months, if not their entire first year. Sharing a room with your baby can reduce the risk of SIDS by up to 50%. It allows you to monitor the baby without bringing them into your own bed.
  • Keep the room cool. Some research suggests that when a baby gets overheated, they may slip into a deeper sleep. This may result in a hard time waking up when their body is trying to tell them to breathe.

Aside from monitoring your baby’s sleep space, you should also take the following measures to prevent SIDS:

  • Keep up on your baby’s vaccinations and well-child visits. Research shows that getting vaccinations on schedule reduces the threat of SIDS by 50%.
  • Breastfeed your baby and use a pacifier. This has been shown to reduce the potential for SIDS.
  • Keep your baby away from cigarette and other types of smoke both before and after birth.
  • Avoid alcohol or drug use during pregnancy.

Premature birth or low birth weight also may be associated with SIDS. Mothers less than 20 years old also may be a factor.


Treatment for sudden infant death syndrome (SIDS)

SIDS can’t be treated since the death happens without warning. Your doctor, however, may be able to help you cope with your loss by recommending sources for grief counseling.

Coping with the loss from sudden infant death syndrome (SIDS)

Anyone who has ever experienced the death of a baby is heartbroken, no matter what the reason. If you’re struggling with this loss, it’s important to give yourself time to heal and possibly even seek counseling. Ask your doctor for recommendations for grief and counseling services. It’s important to talk about what you are feeling and how it’s affecting your work, home, and relationships.

Questions for your doctor

  • Once my child is old enough to roll over, is he or she still at risk for SIDS?
  • Should I wake my child up throughout the night when he or she is a newborn?
  • Is there a test to determine how well my baby is breathing?
  • Can allergies or asthma at a young age cause SIDS?