Parenting • Oct 06, 2014

Understanding SIDS

In my grandmother’s days they called it “blue baby” or “cot death,” the terrible phenomenon doctors now call sudden infant deathSleepSack2 syndrome, or SIDS.  It’s horrible when these babies come into the ER– found dead and blue in their cribs, the parents start CPR and call 911, hoping and praying for a miracle.  It doesn’t usually happen.  Instead we finish the code and call time of death, then comfort the parents.  It’s hard to explain to parents why their healthy baby suddenly died in their crib, without any apparent cause.  Do these babies just die peacefully in their sleep?  Or do they struggle to breathe and suffer?  Could someone have prevented this?  I never had answers to these questions, leaving parents to suffer in our medical ignorance.

Finally, we have some real answers for parents about the cause of sudden infant death syndrome.  

Research published in the medical journal Pediatrics shows that most infants that die of SIDS had underlying brain stem abnormalities.   Specifically, they had abnormalities in serotonin levels and receptors, as well as GABA receptors and 14-3-3 (a protein that regulates serotonin).  So it’s not just suffocation that causes SIDS.  Babies that die of SIDS often have a brainstem abnormality that prevents them from responding appropriately to a lack of oxygen.

When you fall asleep with a blanket over your face, you wake up.  But some babies have immature brain stems that can’t recognize this lack of oxygen correctly, so they don’t wake up and move.

We don’t know what babies have these brainstem abnormalities.  There is no diagnostic test that can detect an infant at risk for SIDS.  Dr. Hannah Kinney, the author of this and many other studies on SIDS, hopes to one day develop such a diagnostic test.  For right now, though, SIDS can be prevented by keeping babies in safe sleep environments, putting them to sleep on their backs and away from suffocation hazards.  In her conclusions, Dr. Kinney emphasizes the need to continue practicing safe sleep for infants.

The “ABC’s” of SIDS help us remember how to keep our babies safe while sleeping:

Babies should sleep ALONE, on their BACK, in a CRIB.  

Yet these ABC’s of safe sleep are the center of controversy, especially among breastfeeding mothers who share a bed with their baby.  Bed-sharing increases the risk of infant suffocation.  The vast majority of pediatricians agree that the safest place for a baby to sleep is in the same room as their mother but not in the same bed.

Dr. Sears, Dr. McKenna, and Dr. Burke are three pediatricians well known for supporting bed sharing, against research that shows cosleeping increases risk of SIDS. I applaud their efforts to improve maternal-infant bonding and breastfeeding. But I feel that the death statistics speak for themselves. In 2011, 57 Missouri infants died while sharing a bed with a parent according to the state’s Child Fatality Review program. And the risk of sudden death during sleep increases by 15 times when a parent sleeps in the same bed as an infant. It is true that substance abuse increases risk of bed-sharing death, as does sleeping with your infant on a couch. Parents should be specifically counseled about these risks. But many deaths were not associated with substance abuse or couch sleeping.

Supporters of bed sharing often tell me that humans have bed-shared with infants for most of history. The difference today, however, is that modern American bedding is much softer and more prone to causing suffocation than the kind of bedding that has been used for most of antiquity. We also do not have statistics on how many infants died while bed-sharing through history.

Here are the most common questions I hear about safe sleep:

“How long should my baby sleep on his back?”

The American Academy of Pediatrics recommends that babies sleep on their backs until they are one year of age.  As a mother, I know this is hard to accomplish!  Put your baby to sleep on his back from the time he is born and let him learn to be a back sleeper.  Do not let him sleep on his belly even if he is on your chest.  Do not let him sleep on his side.

“What if my baby spits up while he is sleeping on his back? Will he choke?”

No, neurologically healthy babies cannot choke on their own spit-up, even if they are sleeping on their backs. They may cough a bit but this is normal.

“I have a crib set with a bumper, blanket, stuffed animal and other matching pieces. Is it safe?”

No… Nothing goes in a crib except the baby and a tight fitting crib sheet.  The “crib sets” marketed by many retail stores include many unsafe items. Never use a blanket in your baby’s bed except to swaddle the baby as described below. Bumpers are not recommended because many experts feel they are a suffocation hazard. Never put pillows, blankets, stuffed animals, or other objects in your baby’s bed.

“Can I swaddle my baby like they did in the nursery at the hospital?”

Yes, you may swaddle your baby tightly until he knows how to get out of his swaddling blanket, which usually occurs within the first month. “Wearable blankets” and swaddling blankets with Velcro closures are now highly recommended to keep your baby warm and safely swaddled. They can also help your baby sleep for longer periods of time at night, which means you get more sleep, too!   Be careful that your baby is not too warm.

“Can I use a sleep positioner or wedge?”

Sleep positioners and wedges are now considered suffocation hazards. Only a few years ago these were marketed as SIDS prevention devices, yet now they are known to be dangerous. If your baby spits up a lot or has been diagnosed with gastroesophageal reflux, you may consider raising the head of the crib mattress. Remember, nothing goes in the crib except the baby and a tight fitting crib sheet.

“I like to sleep with my baby, especially when she needs to feed during the night. Is this safe?”

Sleeping with your baby in the same bed puts your baby at significant risk for suffocation. It is especially dangerous to sleep with your baby on a couch, a waterbed, or a bed with a comforter. Sadly, many babies die when they get wedged between a parent and a couch cushion or get their faces buried in bedding. As a breastfeeding mother myself, I know how hard it is not to co-sleep while breastfeeding. Breastfeeding itself reduces SIDS risk and has many other benefits to mother and baby, so please don’t let a fear of suffocation discourage you from breastfeeding.  Bedside bassinets and other cribs can make life easier when your baby wakes frequently in the night for feeding. Be sure that your baby’s bed is SIDS safe, though. Many beds such as “Moses baskets” and beds with soft bedding and blankets are not safe.  Personally, I recommend “co-sleepers,” three-sided cribs that abut the edge of a parent’s bed. Most co-sleepers meet safe sleeping recommendations. They are especially helpful for breastfeeding mothers.  It is easy to breastfeed even every 1-2 hours as needed, then simply place your baby back in her “co-sleeper” crib where you know she is safe and can sleep soundly. And your feet never have to touch the floor. Of note, the American Academy of Pediatrics feels there is insufficient research to recommend for or against “co-sleepers.” I, however, do recommend them as a sort of compromise between bed-sharing and crib sleeping. I feel co-sleepers really are the best solution to optimize breastfeeding and maternal-infant bonding while minimizing risks of suffocation/SIDS.

Additional resources regarding SIDS are available from SIDS Resources, a St. Louis-based not-for-profit network providing free bereavement services for Infant Loss and educational information relating to Sudden Infant Death Syndrome.


  • Thanks for writing about the research aspect of SIDS. We entered our daughter into Dr. Kinney’s studies, but were devastated to find out our ME did not take the correct samples at autopsy for the study. I am currently ttc a rainbow baby, and I am very nervous as I have found at least 8 moms online who have lost 2 to SIDS. My daughter died in a safe sleep environment. Being a veterinarian I followed the rules to a T. I would love to talk to you on email about your opinions, genetic tests, etc, on a subsequent baby. Thank you.

  • Jessica Krammes

    I do NOT appreciate the word prevent in any article that is about SIDS! There are no known ways to PREVENT SIDS, only speculation on how to help reduce the number of children who die from it every day!

  • Mary Ellen DeBord

    Dr. Berchelmann, thank you for this article. My brother was a SIDs death. Recently our family has discovered we have a genetic mutation on the MTHFR C677T, which stops the processing from folate to L-Methylfolate, thus reducing the number of neurotransmitters we have that cross the brain barrier that help with the production of seratonin, dopamine, etc. My maternal grandmother had Parkinsons (100% Irish), mom has had migraines, Vitamin B deficiency and now dimentia. We have other numerous issues with SIDs, hypothyroidism, rheumatoid arthritis, a baby with a neural tubal defect, executive functioning, etc. Psychiatriatric research is showing that introducing L-Methylfolate (Deplin) along with 10 mg of Citralopram in dimentia patients is slowing the production of plaque on the brain. Order online the “23andme” kit for $99 to test for the C677T mutation. My husband is heterozygous and I am homozygous. I will let our mother know about your connection between seratonin and SIDS. If only they had known what we know today back in 1947 maybe we could have prevented SIDs and spina bifida deaths! Thank you, Mary Ellen DeBord

  • Laura

    As I read this I can’t help it but it brings so many memories I really wish I would of read this or listen :.(. I just lost my son two months ago he was sleeping in his crib and his father laid him on his side , long story short I wake up to my biggest nightmare having to give ur baby cpr while he is dead waiting for a miracle is the worst pain . Idk how to cope with this there’s so many things I’ve learned now but can’t stip blaming my self for not listening I always wanted my baby so comfy and really warm I didn’t think his crib in a bed sheat was comfy seemed kinda hard to me so I always but warm covers :.( can’t go back in time I just wish I can help someone in some way and even if u think it’s too hard or not comfy it’s thesafest thing for your baby!!! I always though people were crazy or paranoid when they will tell me to not put anything on the crib NOTHING ! Just a crib sheat and now I know why! This can happen to anyone. I hope with time we can reduse the deaths of sids from one mother to another we can all help thank you

  • Hi Cindy, my condolences on the loss of your beautiful daughter.

    I think CBS or MTHFR mutations might contribute. I have both and both my mom and I used to suffer sleep paralysis where we were aware but couldn’t move or breathe. I would even pass out while conscious from the inability to move or breathe. This was terrifying and seemed to have something to do with our limited ability to make dopamine and serotonin for our bodies and without dopamine you can’t move your body and without serotonin, para sympathetic nervous system breathing shuts off and you have to actually concentrate and work to breathe. I think that this is what might have happened to some babies.
    Breast feeding would help this because formula is soy based and that uses up B6 levels and with low B6 levels you get low dopamine and serotonin levels so if they get too low, an individual could lose the ability to move (sympathetic nervous system) and also, if serotonin gets too low, lose the ability to diaphragmatically/ parasympathetic nervous system breathe and then with the sympathetic nervous system paralyzed, there would be an inability of the body to switch from diaphragmatic breathing to the upper chest fight or flight breathing.