Raise your hand if you’ve accidentally woken up your baby trying to feel if they were still breathing. Both of my hands and one foot are in the air. There are days my baby is sleeping so soundly, so peacefully, that I check to make sure her chest is still rising and falling…rising and falling.

Sometimes it’s a joke: “Hey, I haven’t heard the baby in a while; check and make sure she’s still alive!” All parents, though, know too well the lurking fear that something might actually be wrong with their child. Much of this fear stems from the keen awareness of a tragic occurrence known as Sudden Infant Death Syndrome, or variably “crib death.”

In this post, you’ll find:

  • What is really meant by “SIDS” as opposed to other infant deaths;
  • Clarification on what SIDS is not;
  • An overview on what we do know about SIDS;
  • Recommendations on how to potentially prevent SIDS;

Just so you know, I incorporate affiliate links, from which I may receive a small commission at no extra cost to you, to help showcase products I personally own and love, as well as to illustrate certain points or product features.

Everything You Need to Know About SIDS

What is SIDS?

SIDS stands for Sudden Infant Death Syndrome, and denotes a rare but inexplicable incident. According to the Mayo Clinic, a cause of death determination is diagnosed as SIDS only when a seemingly healthy baby dies unexpectedly without any clear explanation, usually during deep sleep.

One study on SIDS notes that SIDS is a diagnosis of exclusion (Latorre, Zambrano, & Moreno, 2016). In other words, no one actually knows what causes an infant to die suddenly in this manner.

It could be one common birth defect that has not been detected, or babies could perish this way for a variety of reasons.

Suffice to say, SIDS is a disease whose first and only symptom is death.

Although the term SIDS is gradually being replaced by SUID (Sudden Unexplained Infant Death), I will continue to refer to the phenomenon as SIDS since it remains the most common reference in conversation.

What SIDS is NOT

Sudden Infant Death Syndrome is not ANY sleep-related infant death. Many people incorrectly brand death resulting from suffocation, strangulation, and overlay as SIDS. However, those tragedies have a clear cause of death.

To be properly understood and prevented, the term should be used in its appropriate context.

Thus, to say, “Crib blankets have been known to cause suffocation. You should refrain from placing blankets in your baby’s to help prevent SIDS,” would be a faulty conclusion. If a baby suffocates from getting a blanket wrapped around its face, then we can reasonably assess the cause of death.

Likewise, to say that co-sleeping increases the risk of SIDS because of possible overlay is also erroneous. If a parent were to roll on a child in a way that resulted in the infant’s death, it would not be classified as SIDS.

As long as we define SIDS in the wrong way, we will have a more difficult time understanding what actually occurs, how to identify symptoms, and how to circumvent it.

What We Know About SIDS

Although SIDS is a diagnosis of exclusion, researchers do have some theories as to what might be fatally malfunctioning in these tiny infant bodies. Some suspect genetic cardiac defects, and other such abnormalities, but one particular explanation seems to have gained both popularity and momentum, and makes the most sense in my opinion.

The Autonomic Nervous System

Researchers believe that SIDS might be caused by a glitch in the autonomic nervous system, which is the system that regulates unconscious functions such as breathing. If you try to hold your breath, you will notice that the longer you hold it, the more you struggle not to involuntarily take a huge gasp of air. That is because you are fighting your autonomic nervous system.

When your brain notices you are not breathing, it begins trying to override your conscious will to force you to breathe again. Your autonomic nervous system is what keeps you alive when you sleep; it maintains all of the functions you don’t consciously think about, and many you might not even know about.

One theory on SIDS is that an underdeveloped infant brain may not know to restart a baby’s breathing (or other autonomic functions) if it stops, in particular during a deep sleep. Thus, if a baby were to stop breathing, its body would starve for oxygen, resulting in death and leaving little to no evidence to its cause.

The Risk Factor

SIDS is very rare, but it does happen. Unfortunately, because it is a diagnosis of exclusion without a true standard by which to qualify and quantify it, we have no way of knowing just how common it is. A SIDS diagnosis is largely dependent upon the experience and knowledge of each individual medical examiner. SIDS might be over-diagnosed, or it might not be identified frequently enough.

Even so, some specific characteristics have been identified that seem to link to an increased chance of crib death. According to the Mayo Clinic, those are:

Sex. Boys are slightly more likely to die of SIDS.
. Infants are most vulnerable between the second and fourth months of life.
For reasons that aren’t well-understood, nonwhite infants are more likely to develop SIDS.
Family history.
Babies who’ve had siblings or cousins die of SIDS are at higher risk of SIDS.
Secondhand smoke.
Babies who live with smokers have a higher risk of SIDS.
Being premature.
Both being born early and having a low birth weight increase your baby’s chances of SIDS.”

Sudden Infant Death Syndrome (SIDS), Mayo Clinic

A study in the Archives of Toxicology point out that,

“In-utero exposure to tobacco smoke remains the highest risk factor for sudden infant death syndrome (SIDS).

Ton, et al, (2017)

The Baby Book cautions that SIDS is most likely to occur after midnight (p. 121).

How to Prevent SIDS

Changing the Way We Think About Infant Sleep

Taking into account the autonomic nervous system theory I introduced earlier, make note in particular for the age most frequently afflicted by SIDS, as listed by the Mayo Clinic: babies 2-4 months of age.

Now think…isn’t that the age at which most parents endeavor to have their baby sleeping through the night? I see the bravado smattered all over Pinterest. “How I got my baby to sleep through the night at X weeks!”

Everyone has advice to help you get your own full night’s rest by training your baby to sleep for as long as possible starting between 8 and 12 weeks, or sooner. It’s the first thing well meaning friends and strangers want to know: “Is your baby sleeping through the night yet?”

Maybe this shouldn’t be our goal.

On the one hand, sleep is critical for a baby’s brain development, but on the other, we have to consider the way our babies come pre-programmed. For the better part of a year, an infant’s sleep cycle lasts around 50 minutes (as opposed to an adult’s 90 minute cycle).

Adults spend more time in deep sleep, whereas babies are pretty evenly divided between light (active) sleep and deep (quiet) sleep. This is a built-in safety feature that “may ‘protect’ the infant against stop-breathing episodes,” as Dr. Sears (et al) note in The Baby Book (p. 120). However, the family of authors also remark:

“The concern arises […] that as a baby learns to sleep more deeply, perhaps the risk of SIDS increases, since sleeping deeper does not always mean sleeping safer. […] Between one and six months, when sleep is deepening and the compensatory mechanisms are not yet mature, there is a vulnerable period when babies are most at risk for SIDS.

*bold text emphasis my own

Would a break from the perpetual sleep deprivation be nice for us exhausted parents? Yes, of course. But is training our young babies to sleep through the night truly what’s best for them, when they might not yet have developed the necessary mechanisms to do so safely?

I, along with professionals more knowledgeable and experienced, would posit that we might actually endanger our infants and put them at greater risk for SIDS by attempting to sleep train them too early.

Breastfeeding and pacifier use

According to available literature, breastfeeding and the use of a dummy (pacifier) both reduce the risk of SIDS (Alm et al, 2015). You might worry that using a pacifier will undermine your attempts to breastfeed, but newer research suggests that this concern is not as serious as people have been led to believe.

See: Are We Confused About Nipple Confusion?

I personally always like to know the “why” behind every claimed correlation, but as seems to be a common theme with SIDS, it remains a mystery why suckling seems to reduce the risk of SIDS. In the case of breastfeeding, the reduced risk could occur because the antibodies in the breast milk protect against infections and illnesses, and/or it could have to do with the tendency of breastfed babies to awaken more easily/often than bottle fed babies (Alm et al, 2015). (Breast-fed babies are usually feed more frequently, and are hungry sooner than bottle fed babies, who may receive a greater quantity of milk in one setting, regardless of whether is is breast milk or formula).

The beneficial association with the use of a pacifier is more speculative and less clear. For the science-y explanation, check out this article.

If you’re in the market for an excellent, all-natural rubber pacifier, I highly recommend the Natursutten.

Related: The ONLY Pacifier That Worked for Our Breastfed Baby


You’ve probably heard more times than you can count that co-sleeping increases the risk of SIDS, but this is a lamentable falsehood because the actual data reflects the opposite.

Dispelling the Myths

The Consumer Products Safety Commission issued a general recommendation to parents that children under two should ONLY sleep in a crib meeting the CPSC’s own regulations, which is why so many parents believe co-sleeping is a dangerous and ill-advised practice.

However, the CPSC did not meet the generally accepted standards for what constitutes a credible scientific study because they did not match controls, or separate out individual variables (The Baby Sleep Book, p. 121). They presented only a total number of infant deaths occurring in an adult bed without looking at contributing factors, or how this number compares to deaths occurring in a crib.

Had they done so, you would see that many more infants die in cribs, sleeping alone, than do in their parents bed from both SIDS and non-SIDS circumstances.

Another group conducted a true case study on SIDS and found that the predominant factor contributing to co-sleeping deaths was the mother’s alcohol consumption and smoking habits. These were the only significant risks in connection with bed sharing (Carpenter et al, 2004).

Sweeden has reduced their SIDS rates to one of the lowest in the world, and they actively promote both pacifier use and sleep sharing as a way to diminish the threat of SIDS. You might be interested to know that the US still has one of the highest recorded rates of SIDS in the world, so clearly something we’re doing, something we’re being taught, isn’t working.

Without going into the countless other benefits of sleep sharing, I’ll try to stay to the point…

Co-sleeping works to reduce the risk of SIDS by essentially providing Baby with a breathing pacemaker. Mom and baby develop sleep harmony, which is where the pair’s sleep stages sync up closely so that both are aware of each other’s presence. This helps to arouse Baby at the proper times and maintain his sleep cycle. The mother’s breathing and heart beat help to regulate Baby’s breathing and heart beat. A baby’s blood oxygen saturation is higher when sleeping with its mother than when sleeping alone in a crib (The Baby Book, p. 120-3).

Sleep harmony also means that the mother will be hyper aware of her baby’s sleep should something go wrong. She is far more likely to notice and be able to respond to a stop-breathing episode with her baby in close contact with her than in a crib across the room, or in a separate room of the house.

Correct positioning

To decrease the likelihood of a stop-breathing episode, parents should proactively position their babies in a way to maximize Baby’s ability to breathe. The recommendation that seems to correlate most significantly in a worldwide drop in SIDS is to place babies in the supine position (on their backs) to sleep. If you choose to swaddle, make sure the swaddle is loose enough that it does not restrict Baby’s ability to breathe easily (Pease et al, 2016). The sleeping area should also be clear of any objects which might trigger a stop-breathing episode such as toys or blankets, even if those objects are unlikely to cause suffocation or strangulation.

A Final Note on SIDS

The knowledge that our babies could be snatched away from us in their sleep without any warning is terrifying. More unsettling is the fact that the cause remains almost a total mystery to us. Not only could the unthinkable strike anyone at any time, but we also have no idea how to effectively prevent it. You are not alone in this fear.

The hardest part is knowing that it is a tragedy perhaps completely outside of our control. As parents, we do everything in our power to prevent harm to our children–we buy special products, baby-proof our houses, install expensive car seats in our vehicles, watch our children like a hawk during all our waking hours. Yet, we have to go to sleep worrying that our baby could silently slip away from us while we take just a few hours of unavoidable rest.

It’s difficult to swallow, but we have to accept that we cannot control everything. All we can do is our very best and trust our instincts.

If you think something is wrong, it very well could be.

Whether your baby sleeps right next to you, or in his or her own nursery, trust your instincts. They are so often right, even in the case of SIDS. Parents relay accounts of sudden uneasiness where they rushed to check their babies and dispel their ‘almost certain paranoia’ only to find that their baby was blue and not breathing. Your instincts will undoubtedly save your baby’s life more times than you will ever even know.

If you want to read more in depth about SIDS and baby sleep, I highly recommend The Baby Book and/or The Baby Sleep Book, both from the Sears Family Library collection.

Do you ever double check your sleeping baby “just to be sure?” Have you accidentally woken them up this way? Let me know in the comments!


Alm, B., Wennergren, G., Mollborg, P., & Lagercrantz, H. (2015). Breastfeeding and dummy use have a protective effect on sudden infant death syndrome. Acta Paediatrica. Retrieved from https://onlinelibrary.wiley.com/doi/full/10.1111/apa.13124

Latorre, M., Zambrano, C., & Moreno, S. (2016). Sudden Infant Death Syndrome: Forensic Autopsy Findings in Post-neonatal Deaths. Journal of Forensic Medicine. Retrieved from https://pdfs.semanticscholar.org/897b/53475bc6ec41bd3a9bd1008801b369093613.pdf

Pease, A., Fleming, P., Hauck, F., et al. (2016) Swaddling and the Risk of Sudden Infant Death Syndrome: A Meta-analysis. The American Academy of Pediatrics. Retreived from https://pediatrics.aappublications.org/content/137/6/e20153275.full

Sudden Infant Death Syndrome (SIDS). Mayo Clinic. Retrieved from https://www.mayoclinic.org/diseases-conditions/sudden-infant-death-syndrome/symptoms-causes/syc-20352800

Sears, W., Sears, M., Sears, R., & Sears, J. The Baby Book. (2013). Print.

Sears, W., Sears, M., Sears, R., & Sears, J. The Baby Sleep Book. (2005). Print.

Ton, A.T., Biet, M., Delabre, J., Morin, N., & Dumaine, R. (2017). In-utero exposure to nicotine alters the development of the rabbit cardiac conduction system and provides a potential mechanism for sudden infant death syndrome. Reproductive Toxicology. Retrieved from https://link.springer.com/article/10.1007/s00204-017-2006-x

Hey mom friend

I’m Katie!

I want to encourage you to find your own parenting style by putting on your mom genes and tailoring your parenting instincts.

I believe that you are the best parent for your child, and I want to help you believe that, too.

If we haven’t met yet, come introduce yourself with an email, or on Instagram!

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