12 SIDS Symptoms and Causes Every Parent Needs To Know

September is Child Safety Month. Here at Ready. Set. Food! we’re dedicating the month to sharing ways to keep your little one safe while sleeping, eating, and in the car, based on parents’ most common concerns. Today, we’re covering how to help reduce the risk of sudden infant death syndrome.

Learn sudden infant death syndrome (SIDS) causes and symptoms, plus actions parents and caregivers can take to help reduce a baby’s risk for SIDS.

Sudden infant death syndrome, or SIDS, is a heartbreaking occurrence where a baby dies in their sleep. This usually occurs without warning, making SIDS even more terrifying.

(Because of how unexpected it is, doctors sometimes call it SUIDS, or sudden unexpected infant death syndrome.)

SIDS is relatively rare, with about 3,400 U.S. infants under 1 dying from SIDS per year.

But it's still vital for all parents to understand what SIDS is, symptoms to look out for, and causes of SIDS, because there are ways to reduce your baby’s risk.

Here are the SIDS symptoms and SIDS causes every parent must know. We’ll also cover how to help reduce the risk of SIDS.

Are there SIDS symptoms to look out for?

Alarmingly, there actually aren’t symptoms that occur before a baby dies from SIDS. The babies who die from SIDS usually seem perfectly healthy before going to bed. So, that makes knowing the causes of SIDS, and ways to help reduce SIDS risk, even more vital.

12 SIDS “causes” all parents must know

Although scientists and doctors don’t understand the true cause of SIDS yet, there are several known risk factors that make a baby more likely to die from SIDS.

When researchers talk about SIDS risk factors, they refer to something called the “triple risk model.” This refers to a combination of three types of risk factors thought to lead to SIDS: “a vulnerable infant, a critical developmental period, and an outside stressor (or stressors).”

Some SIDS risk factors are out of your control, but other risk factors can be prevented. And in many SIDS deaths, unsafe sleep environments are thought to play the biggest role. Here are the most common risk factors that can lead to SIDS.

1) Age younger than 6 months

We don’t yet know why this plays a role, but the majority of infants who die from SIDS are younger than 6 months old. Infants between 2 and 4 months of age are most at risk.

2) Brain abnormalities

Some babies who die of SIDS appear to have abnormalities in the hippocampus, the part of the brain that affects breathing and waking from sleep.

One study supported by the National Institutes of Health (NIH) found that 40% of a group of babies that died from SIDS had an abnormality in one part of the hippocampus.

3) A respiratory infection

Some babies who die of SIDS have a respiratory illness (such as a cold), which may make it more difficult to breathe. SIDS deaths are more common in winter, when respiratory infections circulate the most.

4) Was born prematurely or has a low birth weight

One study has shown that preterm and low birth weight babies are up to four times more likely to die of SIDS.

Babies born prematurely, or that have a lower birth weight, may be at higher risk for SIDS because key parts of their brain might not be fully matured. This might mean that it’s harder for their brains to control routine processes like heart rate and breathing.

5) Genetic factors

It seems like certain genes play a role in SIDS risk. This means that siblings of babies affected by SIDS are at increased risk.

6) Exposure to secondhand smoke

If baby is exposed to harmful chemicals from secondhand cigarette smoke, whether inside or outside the womb, this may increase their risk of SIDS.

Baby could be exposed to secondhand smoke in one of three ways: prenatal exposure when their mother smokes while pregnant, prenatal exposure when their mother is exposed to secondhand smoke, and exposure to secondhand smoke after birth.

7) Prenatal exposure to alcohol or certain drugs

Similarly, if baby is exposed to alcohol or certain drugs while in the womb, their risk of SIDS is increased.

8) Sleeping on the stomach or side

As research from many sources has shown, babies who sleep on their stomach or side are at greater risk of dying from SIDS. The stomach and side sleeping positions put them at risk for breathing difficulties and suffocation, and increase their risk of rebreathing the carbon dioxide that they breathe out, all of which may contribute to SIDS.

This is why you must always put baby to sleep on their back --- “back to sleep” is safest.

9) Sleeping on overly soft surfaces

Mattresses and other sleep surfaces that are too soft increase the risk of SIDS and suffocation. So, baby should sleep on a firm crib mattress --- not a soft mattress, waterbed, or other overly soft surface that sinks down. Adult beds and sofas are too soft for baby.

10) Sleeping with loose pillows, blankets, or other objects

Loose pillows, blankets, and other objects (like stuffed animals) on baby’s sleep surfaces are another hazard that increases SIDS and suffocation risk. To keep them safe, baby’s crib should be clear of all of these hazards. They are a danger for baby’s sleep environment until baby reaches their first birthday.

11) Sleeping in the same bed as parents or others

For similar reasons, sharing a bed with parents, siblings, pets, or others puts baby at greater risk for SIDS and suffocation. Baby should always sleep on their own sleeping surface

12) Overheating or being over-clothed during sleep

Getting too warm during sleep increases baby’s SIDS risk. So does being over-clothed for bed (as it may contribute to overheating).

Ways to help reduce SIDS risk

Putting baby to sleep on their back, and creating a safe sleep environment, are the two most vital ways to reduce baby’s SIDS risk.

For more on creating a safe sleep environment for baby, please watch this video from the Centers for Disease Control and Prevention (CDC):

Here are the most important ways to keep baby safe during sleep, and to reduce the likelihood of SIDS.

  • Always put baby to sleep on their back, every time they sleep --- for both naps and at night. Remember: “Back to sleep!”
  • Research from several international reports has shown that back-sleeping lowers baby’s risk of SIDS.
  • Because of those research findings, the American Academy of Pediatrics (AAP) advises that putting baby to sleep on their back is the most important way to reduce SIDS risk.
  • In fact, after U.S. public health agencies launched the “Back to Sleep” awareness campaign, and rates of putting babies to sleep on their backs more than doubled, SIDS deaths dropped by over half.
  • For the safest sleep, babies must always sleep on their backs until they reach their first birthday.
  • Baby must have their own separate crib, bassinet, or other sleep surface. Never have baby share a bed with anyone, as sleeping in the same bed as others increases SIDS risk. Twins and multiples should also never share a crib with each other.
  • Still, baby should sleep in the same room as their parents or caregiver, with their crib close to their caregivers’ bed, as this reduces SIDS risk.
  • This should be done for at least the first six months of life, and ideally for the first year.
  • Baby should always sleep on a firm and flat mattress, or another firm and level sleep surface.
  • Choose a sleep surface that meets current safety standards, and that does not feel too soft. Cover it with a well-fitted sheet.
  • Don’t put any other bedding in the sleep area.
  • Don’t use crib wedges to prop baby’s head up. These could pose a risk of baby rolling into an unsafe sleep position.
  • Never add any loose objects to baby’s sleep area. “Loose objects” to be avoided include pillows, loose blankets, crib bumpers, and stuffed animals. Loose blankets should never be placed over baby.
  • Don’t over-clothe or over-bundle baby. Dress them in appropriate sleep clothing, including a wearable blanket if the weather’s on the colder side (this way, baby won’t need unsafe loose blankets).
  • Make sure baby’s face and head stay uncovered during sleep.
  • Make sure baby doesn’t overheat during sleep. Be alert for sweating, a chest that feels hot to the touch, and other signs of overheating.
  • Keep baby’s sleep environment at a comfortable temperature --- not too warm.
  • Consider offering a pacifier for naps and bed, as this can reduce SIDS risk.
    • If you’re breastfeeding, wait until breastfeeding is well established before offering the pacifier.
    • If you’re formula feeding, you can start the pacifier whenever you wish.
    • Never force baby to use the pacifier.
    • Never attach the pacifier to a string, blanket, clothing or anything else that could increase baby’s strangulation or suffocation risk!
    • Breastfeed baby if possible, as breastfeeding has been shown to lower SIDS risk.
    • But do not breastfeed in bed if you think you’re going to fall asleep, as this is bed sharing that increases baby’s SIDS risk.
    • Keep baby away from cigarette smoke.
    • Avoid any sleep products that go against the safe sleep recommendations of the AAP. Be especially wary of products that claim to “reduce SIDS risk,” but really create an unsafe sleep environment.

    Introduce Allergens Safely and Easily with Ready. Set. Food!

    All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

    These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.  If your infant has severe eczema, check with your infant’s healthcare provider before feeding foods containing ground peanuts.