Research & Science
Jun 20
· Written By
Ted Handler, MD

Back to Sleep: A Simple Recommendation to Reduce Chances of SIDS

Last month, researchers in Massachusetts and Denmark published the collaboration for a working paper on sleep positions. The study reiterated what we already knew: it’s safest to place babies to sleep on their backs. The kicker, though, was how they shined a spotlight on the abrupt, dramatic improvement in child health outcomes when Denmark enacted a country-wide recommendation to place babies on their backs to sleep.

Famous economist and baby-data guru, Emily Oster, has a great summary of the findings on her substack here. Essentially, the country of Denmark enacted the recommendations to place babies on their backs for sleep abruptly in December, 1991. Those recommendations were (and continue to be) conveyed by nurses that visit the homes of new parents after the birth of their child in Denmark. The below graph illustrates a profound drop in SIDS deaths. The vertical line in the middle bifurcates the time period before and after the recommendations were introduced. 




Pretty profound! The researchers estimate this recommendation saved between 11.5-14.5 lives per 10,000 births. If that kind of data science is hard to wrap your mind around, we can try to extrapolate it to the US. In 2019, there were 3,747,540 births in the US. This means that simply flipping babies from their stomachs to their backs would save anywhere from 4,309 to 5,434 lives in a year.

Remember, the shift in numbers is particularly dramatic for Denmark: prior to the recommendation change, Danish nurses were recommending that babies be placed exclusively on their stomachs for sleep. Of course, most babies are not necessarily placed to sleep on their stomachs, but understanding this rate of lives saved helps us to appreciate just how important being placed on your back to sleep is.

Tidbits from Pediatric Specialists 

What about spit up? One question I get a lot in practice is, “how can I place my baby down on their back? They spit up all the time. Won’t they choke on their vomit?” I understand this question. It’s a huge problem with adults who’ve drank too much alcohol. It’s key to remember context here: adults have poisoned themselves when they choke on their vomit. Babies, on the other hand, have evolved to spit up. They’re born with stomachs as small as your thumbnail. The only way to grow their gastric capacity is by feeding them and, often, over-feeding them a little. This is what spitting up is: expulsion of the stomach’s overflow. Should you still burp your baby after each feed? Absolutely. But should you lay awake at night worrying that your baby will spit-up while on their back? Don’t worry, they were born for this.

What if they keep rolling around? With regards to the Back to Sleep recommendation, Oath’s pediatric nurse, Nurse Judy, adds that she is often asked the following about rolling: “I came in to find my baby on their side. Am I supposed to sit next to their bed and roll them onto their back if they move?” According to Nurse Judy, "once they can roll around, I am much less concerned..I reassure the parents to continue to place them on their back in a safe crib that doesn't have anything soft or cooshy in it, but once they roll over onto the tummies, it is what it is. It’s not reasonable for parents to stay up all night rolling them back over.” This is sound advice, and it lines up with the fact that rolling starts around 4 months, exactly when SIDS risk drops precipitously. 

How do I make sure this is safe? Oath’s sleep consultant Anne Del Valle adds, “parents commonly question sleep positioning and what can or cannot be included in a crib or bassinet, understandably so. I like to keep it simple. Ensuring safe sleep for a baby is imperative - we want to place a baby on their back in a clear sleep space, with just a fitted sheet. Once showing any signs of rolling, we then need to also allow for this skill development and transition away from swaddling. When I think of “back is best”, I think of supporting safe sleep until a baby is developmentally capable of sleeping on their side or tummy, all while keeping their crib nice and clear, which also tends to encourage parent peace of mind.” 

Ted Handler, MD
Ted Handler, MD

Founding Pediatrician at Oath Care and general pediatrician in the San Francisco Bay Area.