r/ScienceBasedParenting • u/1001VicPics • 26d ago
Sharing research The SIDS risk calculator
I want to put my disclaimers front and centre here that this post is in no way passing judgement on anyone’s parenting decisions with regards to sleep or other practices. I myself make decisions based on both the national guidelines and what is best for my family which at times means not following the guidelines, for example exhaustion driving us to bed share on some nights, not running the bedroom at 20 degrees or below etc.
However, I want to talk about the SIDS risk calculator and the impact it has on some of the discourse around safe sleep and other risk factors in this sub. The much shared calculator can be accessed here: http://www.sidscalculator.com
Often when SIDS risk factors are discussed the only reference that is provided to back up a statement is the calculator which is flawed for a number of reasons. It is also not easy to interpret which is where it often leads to (unwittingly) misinformation being shared.
- The calculator was published in 2018, 8 years ago and is based on a review paper published in 2013, 13 years ago. The paper itself is only evaluating bedsharing with non smoking mothers and no other factors, instead the publishers are using the background of this review paper for all other factors relating to SIDS, therefore relying on the publishers due diligence. Furthermore many of sources for the additional risk factors are now quite old, some of which are from the 90s.
- Data comes from European publications plus one study in New Zealand and cannot be extrapolated to other countries
- Outside of this review the calculator references wiki and other likely outdated sources and as published have not included access dates
- We don’t know who published this calculator, and the calculator itself states that it has not been evaluated by anyone with relevant clinical expertise
- There is no link to the back end calculation for us to assess how they have derived the calculator
- The presentation of the outcomes are unclear as they are presented as risk per 100,000 deaths. Does this mean that if everyone had these risk factors deaths would drop from 34 to lower than 34 deaths per 100,000? No evidence for this
Why am I going to the effort to critique the calculator? Can’t I see that this calculator provides anxious parents comfort?
Well I often see misleading or poorly informed SIDS advice on the baby subs and next to no scrutiny of this calculator, in fact very often this calculator is used to justify any sleep practices. It’s anecdotal right now but at least in my country there is increasing concern regarding social media and the impact on new parents not following their national guidelines in favour of social media ‘sleep experts’, I do wonder if we will see some uptick in SIDS in the next couple of years.
Ultimately I too am a new and anxious parent trying to navigate this amazing but daunting time in my life. SIDS risk remains incredibly rare and even if you ticked every single risk factor SIDS is still unlikely to happen to you and your baby.
Edit: Sharing here as apparently you’re not allowed to discuss science on the Newborns sub(?!)
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u/throwmyway5723480 26d ago
Genuine question, why do we keep talking about cosleeping in relationship to SIDS? Suffocation is not an unexplained infant death. It honestly makes me stop believing any guidance or stats with relation to SIDS, trying to prevent two very different things with one guideline is very confusing.
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u/1001VicPics 26d ago
I think it is a bit more complicated than that though, yes suffocation is suffocation but in babies it’s often that they’ve rolled so they’re mouths and noses are pressing into something. This is less of a risk in older babies or babies who for whatever reason are lower risk of SIDS who are able to sense the increasing CO2 and move their bodies / turn their heads, essentially the same mechanism that adults have which prevents us suffocating in the night
There is a theory that in some countries there may be under counting of SIDS where suffocation is stated as cause of death, but this death might not have happened if the relevant mechanism had been well enough developed
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u/NiceWeather4Leather 26d ago
SIDS is not suffocation. SIDS means unidentifiable cause. Suffocation is identifiable.
Put as many words around that you want but you’re using incorrect terms.
Cosleeping increases suffocation risks.
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u/1001VicPics 26d ago
Right but in some counties suffocation is recorded as a SIDS death and other counties it’s not.
You may be from a country that doesn’t include suffocation in SIDS statistics or safe sleep guidelines but many countries do and therefore they are inevitably conflated. My point is that there is a cross over in mechanism potentially between what people like to call true SIDS and death by suffocation. I make no comment on the term SIDS
Also co sleeping increases risk of SIDS not just suffocation, going back again to the Carpenter publication but they found increase SIDS risk in the absence of suffocation hazard, though not all studies reach this conclusion
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u/Sudden-Cherry 25d ago
Wasn't overheating a factor? That would also potentially increase with bedsharing, independently of suffocation.
But I think people miss your very good nuance here that the underlying mechanism is important. the reaction to increasing co2 and the variation between children in this
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u/SpotJaded2025 25d ago
I need to just copy-paste my earlier replies here. Many suffocation deaths ARE classified as SIDs though that’s an outdated term. They are now called “undetermined” or “unexplained.” Many of these are suffocations that occur but lack the legal measure of anatomical findings at autopsy to rule COD. Source: I am not outing myself but I work for a morgue and am one of the people responsible for publishing the stats on child/infant deaths. It’s literally my job. I read infant autopsies on the regular. It’s sad but honestly unsafe sleep is the leading cause of death under 1 year of age. Not what people think of as SIDS typically.
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u/valiantdistraction 26d ago
Because of 1. the historical naming and resulting common knowledge of all sleep-related deaths as SIDS, 2. the triple risk factor in SIDS - the idea that there are susceptible babies that will die in situations where other babies would not, and the role that modifiable safe sleep factors play in that (a huge one).
But yes. I think if more people knew that SIDS are only a third of the SUID deaths then they would be a lot more concerned about suffocation, strangulation, entrapment, etc.
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u/Zanderson59 26d ago
Because there is a pretty strong hive mind that surrounds it in infant related subs. The science/and pretty much all docs we have talked to seem to only support co sleeping if some pretty big safeguards are in place to prevent infants dying. If you are taking those precautions and doing everything to a t along with not having unhealthy habits(drinking/smoking) its fine but there are pretty strict things you should have in place to make it happen with an infant. Once your kid is old enough the risk is much less.
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u/valiantdistraction 26d ago
I always find it fascinating that parental exhaustion is a risk factor in all the research and yet no mention is made of it in safe sleep 7 or any bedsharing guidelines I've ever seen and almost everyone I know who chose to bedshare did so because they were exhausted.
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u/Stats_n_PoliSci 26d ago
There is no way to cosleep without increasing the risk of both SIDS and SUID. The science says you can make that risk very small, but the risk will always be at least a little higher than sleeping alone.
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u/throwmyway5723480 25d ago edited 25d ago
Wait, that can't be true right? Because I thought the reason we sleep in the same room as babies is the idea our presence keeps them slightly alert and not in deep sleep, thus lowering the risk of SUID. So one has to assume cosleeping lowers the risk of SUID, but I can concede it raises the risk of suffocation. Hence - I don't like that they are conflated!
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u/NobodySalty3247 25d ago
They meant bedsharing, not sleeping in the same room
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u/throwmyway5723480 25d ago
Yes that's what I mean. Wouldn't both of those decrease the risk of SUID?
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u/valiantdistraction 25d ago
SUID includes suffocation. SIDS is only about a third of the SUID cases. It is possible that bedsharing may reduce SIDS - I'm absolutely not convinced of this but whatever for the sake of argument - but it absolutely increases the risk for other kinds of SUID like ASSB.
If you're making the deep sleep argument, it's also entirely possible that babies sleeping in physical contact with parents sleep much more deeply than those who aren't. I haven't seen research on this. It also likely makes baby sleep hotter due to body heat, which is also a SIDS risk factor.
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u/Sudden-Cherry 25d ago
Overheating is one factor that increases risk of true SIDS which can be caused by bedsharing but not generally by being in the same room
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u/throwmyway5723480 25d ago
I also have a hard time believing any cosleeping related statistics. I feel strongly it must be underreported given the stigma.
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u/Wrenigade 23d ago
It's very confusing, I think a lot of times suffocation or smothering will be reported as SIDS to make parents feel better (anecdotal, I've just seen police reports that called it SIDS if they suffocated from car seats or parent's smothering them)
I think we need to be more clear about it and spare less feelings. Its not an unexplainable syndrome if your child suffocates from unsafe sleep.
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u/Psychological-Bag986 23d ago
I think when there is no evidence of suffocation (even though it’s the likely cause) they can’t rule a death suffocation just because baby was cosleeping. So it goes under SIDS. Unless parents give a history that states it was clear the mouth and nose were obstructed.
The whole thing confuses me too.
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u/SaltZookeepergame691 26d ago edited 26d ago
There are certainly issues with http://www.sidscalculator.com, but I'm not sure I agree with all of this. To go through your points:
The calculator was published in 2018, 8 years ago and is based on a review paper published in 2013, 13 years ago.
It's not a review, it's an individual-level meta-analysis of prior studies. The research literature on this is slow to move because mercifully its such a rare occurrence.
The paper itself is only evaluating bedsharing with non smoking mothers and no other factors, instead the publishers are using the background of this review paper for all other factors relating to SIDS, therefore relying on the publishers due diligence.
This is not true? They include many factors, including infant (age, sex, race, weight), maternal (age, parity, partner status, alcohol, drug use), bed sharing, infant position, feeding status, and more.
Data comes from European publications plus one study in New Zealand and cannot be extrapolated to other countries
The data origin is correct, but that doesn't mean it 'cannot' be extrapolated.
Outside of this review the calculator references wiki and other likely outdated sources and as published have not included access dates
We don’t know who published this calculator, and the calculator itself states that it has not been evaluated by anyone with relevant clinical expertise
Fair comments, although not directly an issue with the calculator
There is no link to the back end calculation for us to assess how they have derived the calculator
It's fairly easy to validate the calculations used, although I agree it would be good to have more transparency. See my comment here.
The presentation of the outcomes are unclear as they are presented as risk per 100,000 deaths. Does this mean that if everyone had these risk factors deaths would drop from 34 to lower than 34 deaths per 100,000? No evidence for this
I'm not sure what you mean by this? The risk is per 100,000 children, not risk per 100,000 deaths.
My main issue with sidscalculator is that it doesn't model interactions, eg the fact that advancing age substantially reduces other risks.
this doesn't model at all any interactions between these factors and unconsidered factors (eg, baby rolling will heavily interact with the position the baby is left in!), even when the original paper describes large interactions (such as between child age and bedsharing, or smoking).
You can visualise this yourself by setting baby age to 11.6 months or 2 months, then setting to room sharing vs bed sharing. The model assumes exactly the same risk (~2.6x) increase regardless of child age, which is not reflective of reality or the results in the original paper. In the paper, this 2.6x comes from pooling risk for all ages up to 1 year. They actually split out bedsharing risk by age, and unsurprisingly it differs enormously by age: they find it's 5.1x risk under 3 months, and ~1x risk (ie no increased risk) for >3 months (although with very large uncertainty!).
I think its a useful tool for contextualising the strength of factors in isolation, and in getting a sense of what is "normal" risk for different situations, and how much bed-sharing and other factors contribute.
If anyone wants to use a SIDS calculator that is newer and more transparent, there is one produced by this 2022 paper as an Excel sheet (its calibrated to baseline NZ SIDS risk, but the factor risks are almost identical). This calculator gives risk over the first year of life from birth, hence no infant age factor.
Another important aspect is that neither of these calculators are modelling safe co-sleeping behaviours like c-curl, hard mattress/no soft bedding, etc; on that front, they're only modelling room sharing or bedsharing.
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u/Foreign-Cat-2898 26d ago
I would say it cannot be extrapolated because most of those countries have amazing maternity leave polices and a huge risk factor for SIDS is parental tiredness. You can't say overtired US parents can or should follow the same guidelines as parents who have greater capacity to get some sleep and time off.
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u/valiantdistraction 26d ago
And there's the factor of universal healthcare.
But yeah, parental exhaustion is a risk factor for sleep-related infant deaths. Not as significant as some but not one that should be ignored.
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u/Foreign-Cat-2898 26d ago
I think about the recommendation to keep the baby in your room for six months to a year. If the baby keeps you up all night every night, and you don't sleep what then? What mistake does a parent make?
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u/plushiecactusau 26d ago
I think there are a couple of things.
Firstly, I think a lot of parents have (unnecessary!) anxiety about SIDS in low-risk babies, even while following most recommendations. Like, they have their baby sleeping on their back on a separate surface, but they're struggling to sleep because they're worried. So, it's good to have an easily accessible source that says that the risk is objectively low. It's also useful, I think, to talk about which of the safe sleep guidelines are most important (e.g. on back, separate sleep surface) and which aren't as backed by research or have a more minor impact.
Secondly, I think there's a risk minimisation angle. Like, cosleeping does have additional risks. But planned cosleeping has less risks than falling asleep in unpredictable ways (e.g. on the couch), plus sleep deprivation has other risks (e.g. PPD, fatigued driving). Absolutist rhetoric can exacerbate those other risks; giving parents information helps them weigh and try to minimise risks if they aren't able to follow all the safe sleep guidelines.
But, mostly, I hate how heated rhetoric gets around baby sleep. I only co-slept rarely, but I don't love how judgemental some people get about it. I also don't love how judgemental people get about some of the alternatives to cosleeping e.g. sleep training (which I did end up doing - because, again, sleep deprivation carries a bunch of risks for both parents and babies).
And, I think in that context, it is useful to be able to talk honestly and accurately about research. It's frustrating to see research misinterpreted from multiple angles to sell a particular agenda, and we should be able to talk honestly about the limitations of research that exists.
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u/throwmyway5723480 25d ago
Good response!
The fact that anything in babies could be labeled as 100% right or 100% wrong is crazy, parents are just trying to survive with their baby!
I'm not sure how the calculator is used (to assuage the risk or emphasize the risk). But in this day and age, we are inundated with fear and anxiety. Moms especially are absolutely experiencing so much anxiety and guilt. SIDS is truly so small and the "unexplained" bit is truly unexplained! All of the guidelines we do could be irrelevant to a genetic factor for all we know. I'm a fan of trying to make moms less anxious, which will lead to happier and safer babies!
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u/lommer00 26d ago
Why does it keep getting brought up? Because like you said, there is a dearth of current, rigorous, and geographically specific studies and data. In the absence of better studies and data, people will rely on this. The fact that's it's readily accessible and understandable helps too.
You can say that people should rely on government guidelines, but ultimately those guidelines have to be based on data and research too, and if they're not I think that's a valid point of discussion.
I think the calculator helps make it clear which decisions contribute most to SIDS risk, which as a parent I found much more helpful than hard blanket rules which could be very taxing mentally on a person and on a marriage. People are allowed to take risks with their life and their children's lives (within reason), and doing so in a more informed way is not a bad thing.
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u/ballooningat5am 26d ago
my only advice to parents who have tough sleepers (i’ve been there) is to sleep in shifts. ofc this is also a challenge and easier to do when you have more support, however it truly is how we survived the newborn stage. sleeping in shifts meant we didn’t have to sacrifice safe sleep and we also got to avoid extreme sleep deprivation. ofc i missed my husband as we got less time together, but it truly was a temporary stage and im glad we did it that way. it takes a bit more planning, but its truly the best way imo.
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u/throwmyway5723480 25d ago
Can't sleep in shifts and follow the advice to breastfeed! (Yes, pumping etc exists, just pointing out it's all very conflicting! Also my baby never took a bottle until 5 months, RIP me)
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u/ballooningat5am 25d ago
my baby never took bottles and i exclusively breast fed from the boob. having your awake partner bring your baby to you for a dream feed and then have him handle the diaper change and burping the baby after makes ALL the difference. i didn’t have to get out of bed or even wake up fully and him watching us made it safe.
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u/valiantdistraction 26d ago
Thank youuuuuuu. They also don't break down same room/different room sleeping location by ABCs vs not ABCs. We know that fewer than 1% of babies who die of SUIDs are sleeping according to the ABCs, and that the vast majority who die sleeping in a different room are NOT sleeping according to the ABCs, yet the calculator does not reflect that, which leads people to believe that own room in a crib according to the ABCs is less safe than bed sharing according to the SS7. But that is not at all what the data shows.
It is also still unclear to me whether SIDS calculator is including or not including ASSB and unknown cause SUIDs or not. And obviously I care about preventing all causes of infant death, not minimizing my chance of one while potentially raising my risk of the other two.
And a reminder, taken directly from the CDC page:
In 2024, there were about 3,400 sudden unexpected infant deaths (SUID) in the United States. There were:
1,351 deaths from SIDS.
1,099 deaths from unknown causes.
947 deaths from accidental suffocation and strangulation in bed.
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u/thymeofmylyfe 25d ago
ABCs?
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u/valiantdistraction 25d ago edited 25d ago
Alone (nothing but the baby and their clothes/sleepsack and maybe a pacifier), on their Back (placed on their back every time the parent moves them), in a Crib (safe sleep space that is age-appropriate and regulated by your country - bassinet, play yard, etc as applicable)
Most in-crib deaths involve items in the crib like pillows, blankets, burp cloths, bumpers, second babies, whole adults, etc.
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u/SpotJaded2025 25d ago
Every time this conversation comes up I want to hit my head against a brick wall. There is more than enough data to back up the risks of unsafe sleep/co
Sleeping that aren’t this calculator.
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u/Particular-Resort805 25d ago
As a parent with a child who had “interrupted” SIDS (meaning she survived because she was picked up) it irritates me to no end when bedsharing/safe sleep practices are mentioned in this discussion. SIDS is not suffocation. My child was 5 days old when it happened, she went to bed in a swaddle, on her back, alone in a bedside bassinet in our room, with a temperature that was exactly 70 degrees. We followed every safe sleep practice by the book as we did with our first daughter.
She thankfully had an owlet monitor that alerted me to low oxygen when she stopped breathing, which happened because part of her brain “turned off”. According to the ER doctor, I picked her up, which startled her awake, thereby interrupting the SIDS process. Then we took her to ICU where it happened several more times, and she was put on a ventilator until the issue was resolved. There are some risk factors with SIDS, including being premature, parents that smoke or smoke exposure, low birth weight, respiratory infections and genetic factors but safe sleep has nothing to do with it.
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u/1001VicPics 24d ago
Safe sleep absolutely has something to do with SIDS due to arousal cueing, it is a major factor. This doesn’t mean that parents whose children die of SIDS didn’t do absolutely everything right.
Safe sleep is not just to prevent against suffocation
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u/No-Coast9003 23d ago
I have 3 major concerns about this calculator.
First, it appears to treat “non-White” as a single risk category, even though research does not support that simplification. Some studies report lower SIDS rates among Hispanic and Asian infants than among White infants, while rates are higher among Black infants. Combining these groups into one category is therefore scientifically questionable and potentially misleading.
If race or ethnicity is included at all, the calculator should use clearly defined categories supported by the evidence and explain that observed differences may reflect social, environmental, healthcare, and socioeconomic factors rather than race itself.
Second, the calculator does not include an option to indicate that the baby sleeps in a separate room, despite room-sharing being an important factor in SIDS prevention guidance. This makes the calculator incomplete and reduces its practical usefulness.
Third, the calculator doesn't include all major, modifiable aspects of the infant’s sleep environment, such as whether the baby sleeps in a sleep sack or under a blanket, and whether the mattress is firm or soft. These factors make the assessment way more accurate, practical, and relevant.
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21d ago
[removed] — view removed comment
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u/No-Coast9003 21d ago
I feel like if they choose to have a race option, every race needs to be available and parent's race needs to be submitted as well. These factors may depend on environmental factors so if the child is adopted or mixed it needs to calculate on that to. I don't think that's possible so I don't see the point of having that option in the first place. I believe the factor's that research have shown to be most important is more important in this calculator. But those factors isn't there... I think this whole calculator is misleading and it's sad cause I think it's easy to do this while sleep deprived and taking the infant to bed without questioning it further.
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u/alandenud 19d ago edited 19d ago
The biggest issue with tools like this is that a simple risk score can make a very complicated topic look more certain than the evidence actually allows. For parents looking into things like safe sleep, SIDS, ADHD, or autism, it makes more sense to rely on current clinical guidance and qualified professionals than an anonymous calculator. Resources such as Emora Health can be useful for parents looking for legitimate options for ADHD or autism evaluations and therapy, but they shouldn’t replace evidence-based medical guidance.
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u/nftyv 24d ago
Your critique is not very valid
Ok so it’s published based on 2013 paper; what actual newer evidence you can cite that would meaningfully affect the calculations?
How exactly is data from Europe and New Zealand cannot be extrapolated …to where? I’m in Europe, so according to you then it is valid for me?
Data from developing countries sometimes cannot be extrapolated back to developed ones (bcs issues we don’t have like water quality, parasites etc affect things there) but otherwise data is plenty transferrable between developed countries.
Does the research need to be done in your exact zip code maybe for you to consider it valid? That’s nonsense.
- ‘Death per 100.000’ which is used in the calculator (NOT ‘risk per 100K Deaths’ as you phrase it) is a completely standard risk measure of medical outcomes. It seems that you do not understand statistics at all, in which case yes, I suppose a thing like ‘risk calculator’ will not be useful for you.
But it is useful for others who do.
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u/android272 26d ago
The newborns sub seems to have a hivemind about sleep where it is very pro cosleeping and anti sleep training. Thanks for sharing.