Swaddling and SIDS

As if parents don’t have enough to worry about these days: Now they are worried about swaddling and SIDS. I am sure that parents all across the world saw the news come across their Facebook feed and were sent into a panic.

Does swaddling your baby increase the rate of Sudden Infant Death Syndrome? You would think so, to read media accounts of a paper published recently in the journal Pediatrics. Here’s a link, and the reference for those who want to read it.

Pease AS, Fleming PJ, Hauck FR, et al. Swaddling and the Risk of Sudden Infant Death Syndrome: A Meta-analysis. Pediatrics. 2016;137(6):e20153275

Here are some headlines from some of our most respected media outlets. Almost all of them misunderstood the paper’s findings:

New York Times: “Swaddling May Increase the Risk of SIDS”

Washington Post: “Swaddling babies is tied to heightened risk of sudden infant death syndrome”

Yahoo! News: “New Research Suggests Swaddling Could Increase Risk Of SIDS”

Thank God for the Atlantic Monthly and to science writer Adrienne LaFrance.  LaFrance is the only medical and science writer I’ve read so far who detected the flaws in the paper. Here’s the headline:

“About That Scary Swaddling Study: A new meta-analysis seems to link infant swaddling with a higher risk of SIDS. But there’s more to the data than that”

Indeed there is more to the story. Let’s get to the bottom of that study on swaddling and SIDS.

Why Even Study Swaddling and SIDS?

In the early 2000s, there was just as much uncertainty as there is today about the causes of SIDS.  The famous Back-to-Sleep campaign in the US was already succeeding in dropping SIDS rates. Our success was similar to results seen in other countries.  Researchers were stumped. Was it really as simple as all that? How could a silly little change like having the baby sleep on her back reduce the risk of SIDS? Many studies were performed looking at body functions like heart rate and breathing in babies. It was known that swaddled babies were generally calmer and less sensitive to waking up suddenly. The question was asked whether being quiet and less sensitive put a baby at risk for SIDS.

A Look at the Studies

Many studies were done, but most of them were lousy. Pease, et al., who wrote the paper that got all the headlines, decided to perform a “meta-analysis” of all the studies they could find on the subject of swaddling and SIDS. A meta-analysis is considered to be the highest form of scientific study. It looks at all scientific studies of a particular question and sort of pools the results. The idea is that many different groups looking at the same problem collectively get to the truth better than any one study does. It’s never a good idea to rely on only one study to answer a question. The more investigators who come up with the same result, the closer to the truth you are probably getting.swaddling and sids 3

They looked at a lot of studies. Since the 1950’s there have been almost 400 studies asking the question: Is there a link between swaddling and SIDS? Of these studies, Dr. Pease and her colleagues could find only 4 that met a standard rigorous to be considered worthy. And one of these had never been published the data on swaddling. When they were done with their analysis the investigators discovered that they could not easily compare the results of all four studies. So to present their final results they needed to eliminate one study, leaving them with three. Out of 400.

What Did They Find?

After pooling all these data, the investigators found that swaddling increased the risk of SIDS very slightly if the baby was put down on her stomach or side. In other words, it was riskier to violate the “back-to-sleep” rule. It was also riskier to swaddle a baby older than 6 months of age. The most confusing part of the study showed that there was a slightly increased risk to swaddling if you lay the baby on her back. It’s confusing because even so, many more SIDS deaths occurred in un-swaddled babies than in swaddled babies. The so-called “increased risk” was only compared to the comparison (“control”) group.


More Problems

There were other problems with the meta-analysis. The investigators could not be sure that all the studies used the same definition of “swaddling”. Swaddling means different things in different places. Some of the studies lumped together swaddled and “wrapped” babies. It isn’t entirely clear what was being compared. Perhaps more damaging, the pooled studies were so different from one another that it was impossible to eliminate all the features that could confound the results. In other words, they couldn’t really be sure that swaddling was the thing that increased the risk of SIDS!swaddling and sids 2

The Bottom Line on Swaddling and SIDS

  • It’s okay to swaddle, but if you do, lay the baby on her back. Swaddling is only risky if the baby is face down or on her side.
  • Older babies probably shouldn’t be swaddled, but that’s okay, since it’s really difficult to swaddle a six-month old baby anyway. They fight out of the swaddle too easily.
  • Learn to swaddle a baby correctly. There are lots of terrific videos on YouTube that show you how. Here’s one: