Emily Oster

5 min Read Emily Oster

Emily Oster

New Study on SIDS Is Not What the Media Says It Is

Suggestive study, horribly misleading coverage

Emily Oster

5 min Read

Sometimes I know I should write about a new study because it’s published in a major academic journal and everyone is talking about it. But sometimes I rely on you all to flag for me what you really want to hear about. Today is one of those days.

Last Thursday morning, I woke up to a very large number of emails and Instagram messages asking me to please, please talk about this new study on the role of a particular enzyme in driving SIDS deaths. Nearly everyone who wrote to me linked not to the academic journal article but to this news coverage. The title — of the article, not the journal study — is “Researchers Pinpoint Reason Infants Die from SIDS.”

I can see why this caught people’s attention, and I can also see why the emails I got asked things like “Does this new finding mean we can ignore the other advice about back sleeping and pillows in the crib?” It is also, unfortunately, an example of a situation in which media coverage is wildly misleading. In case you do not get to the end of this post, the key takeaway is that all of the safe-sleep guidelines — and especially the guideline about putting your child to sleep on their back — are completely unchanged and extremely important.

Let’s turn to the study itself, which you can see here and is entitled “Butyrylcholinesterase is a potential biomarker for Sudden Infant Death Syndrome.” This paper was published in a journal called eBioMedicine, which I would describe as mid-tier (for the technical among you: impact factor of 8.14).

The basic motivation for the paper is to try to identify a characteristic of infants that would predict vulnerability to SIDS. In general, SIDS deaths are extremely difficult to predict beyond basic correlates like prematurity. There are interventions — behaviors — that we know lower the risks, but even with perfect adherence, SIDS remains a significant cause of death. There is a sense that if we had better predictors of what makes an infant vulnerable, we could better monitor and prevent deaths.

This paper argues for the possibility that butyrylcholinesterase (BChE), which is an enzyme of the cholinergic system, could play a role. The cholinergic system, in case it’s been a while since high school biology, is a brain system that regulates aspects of sensory processing, arousal (wakefulness), sleep, and other neural activity. It relies on the neurotransmitter acetylcholine, and that is processed at brain synapses by two enzymes: acetylcholinesterase (AChE) and BChE.

Dysfunction in this system, and these enzymes, has been explored in a variety of illnesses, notably Alzheimer’s and various types of inflammation.

The broad theory in the paper is that differential levels of these two enzymes could impact SIDS through their role in arousal from sleep, which is thought to play a role in SIDS deaths. There is a lot of discussion at the end of the paper about this theory and of the biological support for it. It seems plausible; the reality is that our understanding of these systems is quite poor, making it difficult to pinpoint a mechanism.

Most of the work in the paper is empirical, using data from Australia. The authors would like to compare the levels of these enzymes for infants who died of SIDS with those who did not, to see if the former group has lower levels. The data approach is smart. They make use of dried blood samples, which are blood samples collected from all infants around two to four days after birth. These blood samples are old — they are collected and stored — but the authors were able to use them to figure out the levels of BChE.

They processed samples and calculated these levels for a total of 722 samples. This included 26 sudden deaths, all deaths classified as sudden unexpected death in infancy (SUDI) over the period from July 2018 to July 2020. They also had 41 deaths of similar-age infants that had a known cause, and the remainder were living infants, used as controls.

The primary analysis in the paper is to compare BChE levels in these three groups. When the authors do that, they find that the BChE enzyme levels are lower in the SIDS deaths than in the matched controls, but that difference doesn’t appear when comparing other deaths with matched controls.

They have a nice visualization of the results, which I’ve included below. These graphs show the range of enzyme levels for the control groups (the blue) and the two groups of infants who died (the two red bars). You can see that the average and range are very similar when comparing the non-SIDS deaths to living controls, but the levels among SIDS deaths are lower. In terms of magnitude, the levels are about 25% lower among SIDS deaths.

One thing that should be clear from this graph is that there is a lot of overlap in these levels. Knowing that a baby had an enzyme level of 4 might indicate a higher risk, but definitely there are many infants with a level of 4 who survive. This is all very distant from being a perfect or close to perfect predictor of anything.

That’s the main paper finding. What I take from this, with the paper alone, is an interesting possibility that should be explored more. The sample sizes are small, and with a new theory like this we always want to see more out-of-sample testing. It would also be important to understand whether there are other characteristics that differ across these groups that might be related to enzyme levels and could be driving this result. It certainly seems plausible that BChE (and AChE) levels are a predictor of SIDS risk, and it is worth more follow-up work to understand it.

My primary frustration is with the media coverage of it and, in particular, the story with the headline I noted above, which it would seem has permeated the Facebook mom groups. There is just nothing in the paper that supports that headline or most of the article. Yes, the paper produces suggestive evidence that there might be a correlation between this enzyme level and SIDS. But to say it “pinpoints” the reason infants die from SIDS is absolutely not true.

Perhaps more problematic is this paragraph:

Previously, parents were told SIDS could be prevented if they took proper precautions: laying babies on their backs, not letting them overheat and keeping all toys and blankets out of the crib were a few of the most important preventative steps.

Though not stated explicitly, the implication is that these steps are now no longer necessary. This is definitely false. Consistently putting infants to sleep on their back has large impacts on SIDS rates. I wrote a number of months ago about the best new evidence on that relationship. If you’re curious, I encourage you to read it here; researchers found a 50% reduction in SIDS risk after back sleeping was encouraged. There’s also high-quality evidence that pacifier use reduces SIDS risk significantly (see, e.g., this meta-analysis). If parents stopped doing these things in favor of some enzyme test, we would lose many hard-won gains, and more infants would die.

The article ends with this:

As the cause is now known, researchers can turn their attention to a solution. In the next few years, those in the medical community who have studied SIDS will likely work on a screening test to identify babies who are at risk for SIDS and hopefully prevent it altogether.

This is totally wrong. The cause of SIDS is not “now known.” There isn’t an obvious solution. It seems possible — remotely possible — that if we see confirmation of the relationship in this paper in other work, there will be some screening for risk. I’m not sure how likely that is, but even if we did get there, the idea that this would prevent SIDS altogether is just … really, really not right.

In conclusion: this is among the starkest examples I have seen recently of how a study can get distorted by the media, show up in mom groups, and go viral for all the wrong reasons.

SIDS is a scary idea for new parents, and lowering the risk is something we all care about. Back sleeping. Pacifier use, if that works for you. No soft stuff in the crib. No sofa sleeping. These are the key interventions to keep your baby as safe as possible.

[Updated 5/16: After this post was released, the article online was updated to remove some of this language and to emphasize the importance of taking these primary SIDS prevention steps.]

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Milestones. We celebrate them in pregnancy, in parenting, and they’re a fun thing to celebrate at work too. Just a couple years ago I couldn’t have foreseen what this community would grow into. Today, there are over 400,000 of you here—asking questions, making others feel seen wherever they may be in their journey, and sharing information that supports data > panic. 

It has been a busy summer for the team at ParentData. I’d love to take a moment here to celebrate the 400k milestone. As I’ve said before, it’s more important than ever to put good data in the hands of parents. 

Share this post with a friend who could use a little more data, and a little less parenting overwhelm. 

📷 Me and my oldest, collaborating on “Expecting Better”

Milestones. We celebrate them in pregnancy, in parenting, and they’re a fun thing to celebrate at work too. Just a couple years ago I couldn’t have foreseen what this community would grow into. Today, there are over 400,000 of you here—asking questions, making others feel seen wherever they may be in their journey, and sharing information that supports data > panic.

It has been a busy summer for the team at ParentData. I’d love to take a moment here to celebrate the 400k milestone. As I’ve said before, it’s more important than ever to put good data in the hands of parents.

Share this post with a friend who could use a little more data, and a little less parenting overwhelm.

📷 Me and my oldest, collaborating on “Expecting Better”
...

I spend a lot of time talking people down after they read the latest panic headline. In most cases, these articles create an unnecessary amount of stress around pregnancy and parenting. This is my pro tip for understanding whether the risk presented is something you should really be worrying about.

Comment “link” for an article with other tools to help you navigate risk and uncertainty.

#emilyoster #parentdata #riskmanagement #parentstruggles #parentingstruggles

I spend a lot of time talking people down after they read the latest panic headline. In most cases, these articles create an unnecessary amount of stress around pregnancy and parenting. This is my pro tip for understanding whether the risk presented is something you should really be worrying about.

Comment “link” for an article with other tools to help you navigate risk and uncertainty.

#emilyoster #parentdata #riskmanagement #parentstruggles #parentingstruggles
...

Here’s why I think you don’t have to throw away your baby bottles.

Here’s why I think you don’t have to throw away your baby bottles. ...

Drop your toddlers favorite thing right now in the comments—then grab some popcorn.

Original thread source: Reddit @croc_docs

Drop your toddlers favorite thing right now in the comments—then grab some popcorn.

Original thread source: Reddit @croc_docs
...

Just keep wiping.

Just keep wiping. ...

Dr. Gillian Goddard sums up what she learned from the Hot Flash  S e x  Survey! Here are some key data takeaways:

🌶️ Among respondents, the most common s e x u a l frequency was 1 to 2 times per month, followed closely by 1 to 2 times per week
🌶️ 37% have found their sweet spot and are happy with the frequency of s e x they are having
🌶️ About 64% of respondents were very or somewhat satisfied with the quality of the s e x they are having

Do any of these findings surprise you? Let us know in the comments!

#hotflash #intimacy #midlifepleasure #parentdata #relationships

Dr. Gillian Goddard sums up what she learned from the Hot Flash S e x Survey! Here are some key data takeaways:

🌶️ Among respondents, the most common s e x u a l frequency was 1 to 2 times per month, followed closely by 1 to 2 times per week
🌶️ 37% have found their sweet spot and are happy with the frequency of s e x they are having
🌶️ About 64% of respondents were very or somewhat satisfied with the quality of the s e x they are having

Do any of these findings surprise you? Let us know in the comments!

#hotflash #intimacy #midlifepleasure #parentdata #relationships
...

Should your kid be in a car seat on the plane? The AAP recommends that you put kids under 40 pounds into a car seat on airplanes. However, airlines don’t require car seats.

Here’s what we know from a data standpoint:
✈️ The risk of injury to a child on a plane without a carseat is very small (about 1 in 250,000)
✈️ A JAMA Pediatrics paper estimates about 0.4 child air crash deaths per year might be prevented in the U.S. with car seats 
✈️ Cars are far more dangerous than airplanes! The same JAMA paper suggests that if 5% to 10% of families switched to driving, then we would expect more total deaths as a result of this policy. 

If you want to buy a seat for your lap infant, or bring a car seat for an older child, by all means do so! But the additional protection based on the numbers is extremely small.

#parentdata #emilyoster #flyingwithkids #flyingwithbaby #carseats #carseatsafety

Should your kid be in a car seat on the plane? The AAP recommends that you put kids under 40 pounds into a car seat on airplanes. However, airlines don’t require car seats.

Here’s what we know from a data standpoint:
✈️ The risk of injury to a child on a plane without a carseat is very small (about 1 in 250,000)
✈️ A JAMA Pediatrics paper estimates about 0.4 child air crash deaths per year might be prevented in the U.S. with car seats
✈️ Cars are far more dangerous than airplanes! The same JAMA paper suggests that if 5% to 10% of families switched to driving, then we would expect more total deaths as a result of this policy.

If you want to buy a seat for your lap infant, or bring a car seat for an older child, by all means do so! But the additional protection based on the numbers is extremely small.

#parentdata #emilyoster #flyingwithkids #flyingwithbaby #carseats #carseatsafety
...

SLEEP DATA 💤 PART 2: Let’s talk about naps. Comment “Link” for an article on what we learned about daytime sleep!

The first three months of life are a chaotic combination of irregular napping, many naps, and a few brave or lucky souls who appear to have already arrived at a two-to-three nap schedule. Over the next few months, the naps consolidate to three and then to two. By the 10-to-12-month period, a very large share of kids are napping a consistent two naps per day. Over the period between 12 and 18 months, this shifts toward one nap. And then sometime in the range of 3 to 5 years, naps are dropped. What I think is perhaps most useful about this graph is it gives a lot of color to the average napping ages that we often hear. 

Note: Survey data came from the ParentData audience and users of the Nanit sleep monitor system. Both audiences skew higher-education and higher-income than the average, and mostly have younger children. The final sample is 14,919 children. For more insights on our respondents, read the full article.

SLEEP DATA 💤 PART 2: Let’s talk about naps. Comment “Link” for an article on what we learned about daytime sleep!

The first three months of life are a chaotic combination of irregular napping, many naps, and a few brave or lucky souls who appear to have already arrived at a two-to-three nap schedule. Over the next few months, the naps consolidate to three and then to two. By the 10-to-12-month period, a very large share of kids are napping a consistent two naps per day. Over the period between 12 and 18 months, this shifts toward one nap. And then sometime in the range of 3 to 5 years, naps are dropped. What I think is perhaps most useful about this graph is it gives a lot of color to the average napping ages that we often hear.

Note: Survey data came from the ParentData audience and users of the Nanit sleep monitor system. Both audiences skew higher-education and higher-income than the average, and mostly have younger children. The final sample is 14,919 children. For more insights on our respondents, read the full article.
...

Happy Father’s Day to the Fathers and Father figures in our ParentData community! 

Tag a Dad who this holiday may be tricky for. We’re sending you love. 💛

Happy Father’s Day to the Fathers and Father figures in our ParentData community!

Tag a Dad who this holiday may be tricky for. We’re sending you love. 💛
...

“Whilst googling things like ‘new dad sad’ and ‘why am I crying new dad,’ I came across an article written by a doctor who had trouble connecting with his second child. I read the symptoms and felt an odd sense of relief.” Today we’re bringing back an essay by Kevin Maguire of @newfatherhood about his experience with paternal postpartum depression. We need to demystify these issues in order to change things for the better. Comment “Link” for a DM to read his full essay.

#parentdata #postpartum #postpartumdepression #paternalmentalhealth #newparents #emilyoster

“Whilst googling things like ‘new dad sad’ and ‘why am I crying new dad,’ I came across an article written by a doctor who had trouble connecting with his second child. I read the symptoms and felt an odd sense of relief.” Today we’re bringing back an essay by Kevin Maguire of @newfatherhood about his experience with paternal postpartum depression. We need to demystify these issues in order to change things for the better. Comment “Link” for a DM to read his full essay.

#parentdata #postpartum #postpartumdepression #paternalmentalhealth #newparents #emilyoster
...

What does the data say about children who look more like one parent? Do they also inherit more character traits and mannerisms from that parent? Let’s talk about it 🔎

#emilyoster #parentdata #parentingcommunity #lookslikedaddy #lookslikemommy

What does the data say about children who look more like one parent? Do they also inherit more character traits and mannerisms from that parent? Let’s talk about it 🔎

#emilyoster #parentdata #parentingcommunity #lookslikedaddy #lookslikemommy
...

SLEEP DATA 💤 We asked you all about your kids’ sleep—and got nearly 15,000 survey responses to better understand kids’ sleep patterns. Comment “Link” for an article that breaks down our findings!

This graph shows sleeping location by age. You’ll notice that for the first three months, most kids are in their own sleeping location in a parent’s room. Then, over the first year, this switches toward their own room. As kids age, sharing a room with a sibling becomes more common. 

Head to the newsletter for more and stay tuned for part two next week on naps! 🌙

#parentdata #emilyoster #childsleep #babysleep #parentingcommunity

SLEEP DATA 💤 We asked you all about your kids’ sleep—and got nearly 15,000 survey responses to better understand kids’ sleep patterns. Comment “Link” for an article that breaks down our findings!

This graph shows sleeping location by age. You’ll notice that for the first three months, most kids are in their own sleeping location in a parent’s room. Then, over the first year, this switches toward their own room. As kids age, sharing a room with a sibling becomes more common.

Head to the newsletter for more and stay tuned for part two next week on naps! 🌙

#parentdata #emilyoster #childsleep #babysleep #parentingcommunity
...

Weekends are good for extra cups of ☕️ and listening to podcasts. I asked our team how they pod—most people said on walks or during chores. What about you?

Comment “Link” to subscribe to ParentData with Emily Oster, joined by some excellent guests.

#parentdata #parentdatapodcast #parentingpodcast #parentingtips #emilyoster

Weekends are good for extra cups of ☕️ and listening to podcasts. I asked our team how they pod—most people said on walks or during chores. What about you?

Comment “Link” to subscribe to ParentData with Emily Oster, joined by some excellent guests.

#parentdata #parentdatapodcast #parentingpodcast #parentingtips #emilyoster
...

Humility. That’s why. That’s the whole reason.

#emilyoster #secondbaby #parentingjokes #parentinghumor

Humility. That’s why. That’s the whole reason.

#emilyoster #secondbaby #parentingjokes #parentinghumor
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Bug season is upon us. Besides annoyance, this can bring up safety concerns, particularly with ticks. They are carriers of diseases, most notably Lyme disease. So what’s the best course of action?

Prevention is key! I suggest:
⭐ Regular tick checks
⭐ Using bug sprays with DEET 
⭐ Wearing long sleeves and pants in the woods

Some parents worry about DEET, but repellants with up to 30% DEET are recommended by both the CDC and AAP. The data says you’re in the clear, so go for it. Enjoy your summer!

#parentdata #emilyoster #tickseason #bugbites #bugspray

Bug season is upon us. Besides annoyance, this can bring up safety concerns, particularly with ticks. They are carriers of diseases, most notably Lyme disease. So what’s the best course of action?

Prevention is key! I suggest:
⭐ Regular tick checks
⭐ Using bug sprays with DEET
⭐ Wearing long sleeves and pants in the woods

Some parents worry about DEET, but repellants with up to 30% DEET are recommended by both the CDC and AAP. The data says you’re in the clear, so go for it. Enjoy your summer!

#parentdata #emilyoster #tickseason #bugbites #bugspray
...