Science on babywearing forward facing, M position and hip dysplasia?

[neilhall]

Everywhere I read about related to babywearing it says that you need to have baby in the “M position” ie knees above bum. Which a lot of inward facing carriers do. Someone warned me about baby facing outwards and said it’s because you can’t achieve said position as easily and the spine isn’t in the correct C position.

Lots of people on this sub say “my paediatrician says this or that” but I can’t find any concrete science relating to the M position and hip dysplasia.

I get that baby needs to have good neck control, and it can be overstimulating. But online it warns of possible hip and spine problems that can come from outward facing. Is there any data / science/ studies relating to babywearing and hip and spine health? Particularly forward facing but obviously any data would be helpful!

We have the ergobaby omni breeze that is meant to put them in the M position when forward facing!

 

[alexander7791]

@neilhall From what I've read, there is some evidence at the population scale that carrying a baby with straightened legs increases the incidence of hip displaysia. Most babies will be fine using a carrier that doesn't support the optimal position, but some won't, and there's no way to know for sure which category your baby is in.

The Hip Displaysia Institute does say that there's really not much concern about short-term use of any baby carrier. So forward-facing as recommended (wait until baby can sit unsupported and then forward face for 20 min or less) should be ok.

Here are some links: https://hipdysplasia.org/baby-carriers-other-equipment/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8688658/

 

[calso]

@neilhall I’m glad you asked this question, I think you are right that there really is not much actual research out there on this topic. I found this review article interesting: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8688658/

What I gleaned from this is that hip dysplasia is most likely to be more influenced by prenatal factors than anything else, but anything that holds a baby’s legs with hips extended and legs together could potentially increase risk for hip dysplasia. Considering that swaddling, strollers, and bucket car seats all put infants in that position, it is unclear to me why narrow-based baby carriers are so emphasized. I know this is an unpopular opinion on this sub, but my personal opinion is that if you follow the safety guidelines (don’t forward face until 6 months/good neck and core control, only do it for 20 minutes at a time), it is perfectly safe. I do think it is not optimally ergonomic for baby or wearer, but that is more about comfort than health. I also think the risk of positional asphyxiation is much more concerning than the risk of hip dysplasia.

 

[tenesia]

@calso

Considering that swaddling, strollers, and bucket car seats all put infants in that position

I'm not sure what you mean by this, none of these things should put baby in a hips extended, legs together position? Swaddling doesn't put any pressure on hips or legs so they should lay naturally (which is typically a diamond shape until they get older), bucket seat keeps them in a reclined seated position spine in a C shape and in strollers, before they have head control they shouldn't be seated so they should be laying flat, like they would in a bassinet or crib.

 

[calso]

@tenesia Take a look at the article I linked. Also, here’s another one: https://scholar.google.com/scholar?...=#d=gs_qabs&t=1685206594154&u=#p=6DCI3JPQLekJ
Note that the research focuses on infants who have risk factors for hip dysplasia or who already have hip dysplasia, and says that baby carriers that allow legs to be in the “M” position may reduce risk. As far as I can tell the evidence is not there to show that container-type devices like car seats, tight swaddling, OR narrow based carriers actually CAUSE hip dysplasia. I am guessing it is difficult to study because of medical ethics, so pretty much all the studies I can find are either analyses of hip dysplasia rates in cultures with different baby carrying practices, or analysis of the hip angles babies display in various carrying devices as compared to the optimal angle achieved by the type of brace used to treat hip dysplasia.

 

[tenesia]

@calso Ah I see, I've never seen swaddling taught in the way the article refers to as "traditional swaddling."

But yea, it would be impossible to determine causal relationship. They can't study babies carried in a "safe" vs "unsafe" position and see what happens a year later. You'd have to control for length of time carried and other practices as well. That would be the only way to determine a causal relationship. Even trying to study different cultures to determine a correlation has its limits because there are many other factors involved. I think the reason a lot of people don't recommend it is because the risk outweighs the benefits not because front carry in and of itself is dangerous

 

[calso]

@tenesia I personally don’t love it (for ergonomic reasons and because having to turn the baby around after 20 minutes is a hassle), but lots of people want to do it and I can understand why. Yes, back carrying is more ergonomic, but also it is more daunting and has safety concerns as well, especially for people who don’t come from a culture where back-wearing is traditional or have access to in-person instruction. Also a lot of people are gifted narrow-base carriers, so I would rather educate people on how to safely use what they have than telling them they shouldn’t use it.

 

[calso]

@neilhall I forgot to mention that I had a baby who was at risk for hip dysplasia due to breech positioning, and I was told to avoid swaddling (sleep sacks and “hip healthy” swaddling were ok), prolonged time in the car seat, and babywearing in the cradle position in ring slings or in narrow-based carriers. All of these recommendations seem evidence-based to me for babies with known risk factors. But also all of that was really emphasized for the newborn stage, once he was 6 months and had been cleared by ultrasound nobody was concerned about him developing hip dysplasia.

 

[dantecak]

@neilhall It’s not great for the wearer’s back. It tends to pull you forward rather than bear the weight on your hips. Back carrying is generally more ergonomic for the wearer, plus baby can put their head down to prevent over stimulation.

Also keep in mind:
- a baby with good head control doesn’t require as much head support inward facing, which allows them to look around more

• And that optimal baby position changes as they age

https://images.squarespace-cdn.com/...523796808-NWBLXH7PCS4KW2WJM0TQ/positionog.JPG

And their spine shape matures
https://www.truehealthct.com/wp-content/uploads/2012/08/baby-spine1.png

 

[katrina2017]

@neilhall The International Hip Dysplasia Institute has a good educational page on baby carriers and hip dysplasia that basically explains that the highest risk for developing hip dysplasia and/or dislocation takes place under 6 months of age and that crotch dangling from a carrier for prolonged periods put babies in higher risk of developing hip dysplasia.

I saw a fit check posted recently of a baby forward facing in a carrier where it almost looked like the carrier was pressing on the child’s neck. Basically, it’s a lot more difficult to get a safe/proper fit in that position, and it’s not recommended for long periods of time.

Baby being uncomfortable inward facing could also be due to a fit issue - it doesn’t hurt to post a fit check and maybe people could offer some tips to help. Otherwise the best option would be to get a carrier that allows baby to be in a high back carry so they can look over your shoulder.

You can do a search for “baby carrier hip dysplasia” on Google Scholar to find primary source literature on the topic as well.

 

[calso]

@katrina2017 I just did a search, I can’t find a single thing linking narrow-based baby carriers to hip dysplasia, but there are a lot of studies indicating that wide-based carriers may be beneficial for hip development.

 

[david]

@neilhall I just want to mention...the reason *why* there isn't a lot of peer-reviewed, "scientific" research on this subject is because performing a high sample, robust study on newborns would be unethical and harmful for the baby. So there's a lot of anecdotal observations from pediatricians, orthos, OTs, etc. that we need to trust and rely on because forcing dozens or hundreds of babies into that position just to get a research paper wouldn't be appropriate.

It's the same with why we don't really know how certain medications affect pregnant mothers and babies -- we just have to make conservative, educated guesses to keep everyone safe and healthy!

 

[aprilagain]

@neilhall I feel like the info others have posted here is answering your question well. I just wanted to say that when you are ready to forward face, I love my ergo omni. If you make sure you get a good fit, make sure you flair the seat base once baby is in it, and do a pelvic scoop, you can definitely get a c shape spine and a pretty ok M shape in the legs!

 

[ktxllc]

@neilhall As already stated, such research on babies would be unethical. Just by looking at it you can sometimes see it is not ok for the baby. For example people with large breasts, big bellies etc, you already can see how the back of the baby is shaped. If you had to be in that position with your back you’d be uncomfortable too. If you keep in mind that a C shape is a natural back shape for a baby, you can imagine how much more uncomfortable it is.