Emily Oster

8 min Read Emily Oster

Emily Oster

Baby Helmets

And a longer discussion of positional plagiocephaly

Emily Oster

8 min Read

Today I want to write about something completely different: baby helmets.

No, I am not talking about bike helmets, which your child (and you) should definitely wear. I’m talking about baby helmets to fix infant head shape. To address “flat head” issues or, more scientifically, plagiocephaly.

Plagiocephaly is one of a number of cranial issues that can occur in infants, related to variations in how the parts of the skull fuse together. Cranial deformities are typically a result of defects present at birth. For example, the most common of these deformities is called scaphocephaly (“hull-shaped skull”), which causes elongation of a segment of the skull and occurs in about 1 in 2,000 live births.

Plagiocephaly, in general, is a deformity that results in a “twisted skull” appearance. It can occur on the front of the face, where one side of the forehead appears more prominent and the ear on that side is higher and farther forward. It can also affect the back of the head, resulting in a forehead that bulges forward on one side and a lower-set ear on the affected side.

This type of cranial deformity can occur as a result of a birth defect (similar to all other cranial deformities), but it can also arise through what is called positional plagiocephaly or deformational plagiocephaly — basically, as a result of holding the same position with the head. The resulting head shape resembles the stylized drawing below.

This problem has gotten a lot of discussion of late, because the incidence of this type of plagiocephaly has gone up significantly since the introduction of “Back to Sleep.”

The Back to Sleep campaign began in the early 1990s and encouraged parents to put their infants on their backs to sleep, to prevent SIDS. (I’ve written about the evidence — which is good — behind this recommendation here.) There is little question that the advice prevented deaths from SIDS, but it was noted as early as 1996 that there was a head-shape side effect. In the pre-Back-to-Sleep period, positional plagiocephaly was thought to occur well under 1% of the time. More recent updates suggest the current share is somewhere between 16% and 45% (see, e.g., this paper and this one).

This isn’t surprising considering the mechanics. Infants spend a lot of time sleeping, and if they spend it all with their head in one position, given the flexibility of the infant skull, there are possible effects. There are some factors that increase the risks for infants. The most important of these are variations in neck rotation — infant torticollis, or other limited ranges of rotational motion, seem to matter. Limited ability to rotate the neck is likely to result in infants always sleeping on one side of their head, and may make it difficult for an adult to vary head position during sleep. This is more common in premature babies and multiple births.

That’s the background. The obvious next questions: Are there any risks to this, and, especially if so, what should be done? Including the question of helmets.

Risks to positional plagiocephaly

The primary concerns here are cosmetic. Severe, or even less severe, forms of positional plagiocephaly can cause variations in head shape that parents (or later, kids) may find upsetting.

There have also been concerns raised about links between plagiocephaly and developmental delays. The idea, if this were causal, would be that variations in skull shape would impact the brain negatively. A meta-analysis of correlational studies suggested some evidence of a link between the diagnosis and motor delays in particular.

However, it seems much, much more likely that the appropriate interpretation of these correlations is, in fact, not a causal one. Motor delays are associated with many things that put infants at higher risk for positional plagiocephaly; it seems more likely that the causality goes in the other direction (or simply that there are other factors that relate to both outcomes).

Treatment

There are, effectively, three broad ways positional plagiocephaly is addressed.

The first is “repositioning therapy,” which is done through parental education. Parents can be encouraged — even before any evidence of an issue — to vary the side of the head their infant sleeps on. When you put your baby down, don’t always have their head the same way. More “tummy time” is another important preventative component, since that strengthens neck muscles and also is time not spent on their back. (I am struck as I write with a vision of my kids trying to do tummy time on this play mat, moving their head up and down until they lost steam, smashed their face into the floor, and started to cry. Ah, memories.)

A second is physical therapy. Physical therapy can address issues of limited neck rotation and can provide a way to scaffold tummy time. Adding physical therapy to the parental education described above is thought to improve prognoses.

Finally, we come to helmets. The idea behind the helmet is that an infant wears it consistently, and it helps reshape the head. Helmets are a commitment. They aren’t painful for babies — reshaping the head is not like how braces reposition teeth — but the intention is that infants wear them 23 hours a day for several months.

This is tough for families, babies get hot, they may be less comfortable snuggling and it’s not a happy situation for many parents. People have trouble following through. On top of this, helmets can cost several thousand dollars (though are sometimes covered by insurance).

With this level of commitment, we’d like to know they work. Do they? There is disagreement. The disagreement comes down to two papers.

The first of these papers was published in 2015 in the journal Plastic and Reconstructive Surgery. In it, the authors take a sample of about 4,000 babies and assign them to either conservative approaches (repositioning, or repositioning plus physical therapy) or to helmet therapy. Their headline result is that resolution of the problem occured in 77.1% of the first group and 94.4% of the helmet group. In addition, among those who started with conservative management and then ended up with a helmet, 96.1% had resolution.

In principle, this study seems very compelling. However, the devil is in the details, and when I say the babies were “assigned” (which is the language from the abstract), it doesn’t mean “randomly assigned.” A random-assignment version of the data above would be convincing. In fact, the way infants were assigned to these groups was based on a full evaluation and consultation with the treatment team. This introduces all sorts of issues — helmets may have been assigned to families with a greater likelihood of adherence, to infants with different types of problems, and so on.

The second paper was published in The BMJ in 2014. In this paper, the authors took a sample of 84 infants and randomized them into either helmet therapy or nothing (“natural course”) and followed them over time. They found no significant difference in the two groups in the resolution of the condition. In both groups, resolution occurred in about a quarter of the children, considerably lower than in the 2015 study, likely due to the inclusion in that study of a higher-risk group.

The obviously helpful aspect of this study is that it was randomized. But there are still a lot of things for people to complain about. It’s small, and, as the researchers disclose, only about 20% of the people they tried to recruit agreed to be in the study. This makes us concerned about the possibility that the effect in the overall population might not be the same as what we see in this selected group (a question of “external validity”). Adherence to the helmet therapy wasn’t uniform, and the authors do not distinguish in the analysis between infants with moderate versus severe issues. Also of note, they exclude a number of higher-risk infants. But … it’s randomized!

In the end, the debate over helmets in the data really hinges on whether you like the larger study that isn’t randomized or the smaller one that is, recognizing that both are flawed. I favor the randomized one.

Putting this all together, there is a reasonable middle approach, which is effectively what the Congress of Neurological Surgeons suggests in its review. The first line of defense should be non-helmet-based, including both parental education and physical therapy. Helmets may be an option if that is ineffective or if the situation is severe. But they shouldn’t be the first line.

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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
...

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
...