We were told just prior to checking out of the hospital that sleeping with the infant, along with side-sleeping and front-sleeping, increases the risk of Sudden Infant Death Syndrome (SIDS).

I was under the impression that safe cosleeping habits were just that, safe.

In general, these safety guidelines include:

  • No extra objects in the bed: no pillows, no stuffed animals, no loose blankets
  • Sleeping surface is firm
  • Parents are not smokers, are not intoxicated, or on any medication that causes drowsiness
  • Parents are not obese
  • Parents are not sick
  • And much more

That is far from a complete list. The two lists I linked to are more comprehensive, but they don't all have the same things.

Have there been any studies about whether safe-practice bed-sharing increases the risk of SIDS? I'm looking for information showing a correlation or causation between best-practice bed-sharing and SIDS risk.

  • 6
    My gut feeling is that the hospital is discouraging the practice since it's easier than running through (and hoping sleep-deprived parents remember!) a long list of safety guidelines. But since that's a hunch, not science, I am leaving a comment and look forward to seeing well-referenced Answers ;)
    – Acire
    May 11, 2015 at 19:16
  • I have not seen anything that would suggest an increased risk for SIDS for co-sleeping alone. All my sources (and it feels they are happily copying from each other) state that co-sleeping can increase the risk if ... (and here comes the usual list of soft bedding, intoxicated parents etc. we all know).
    – Stephie
    May 11, 2015 at 19:29
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    Just for clarification, are you talking about the child sleeping in the bed with you, or nearby in the same room, or a combination of the two (nearby, then in bed to nurse?) May 11, 2015 at 20:05
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    @anongoodnurse As always, your expertise is appreciated. I was assuming they were defaulting to the easiest solution (don't recommend to anybody) instead of attempting to evaluate the parents' bedding, general health, and making a decision based on that; however, your answer provides a much different picture of the current research than the question. :)
    – Acire
    May 11, 2015 at 22:53
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    Related Skeptics.SE Question: Is “co-sleeping” (infant sleeps in bed with parents) safe?
    – Acire
    May 12, 2015 at 15:20

4 Answers 4


Unfortunately, sleeping anywhere - bed, sofa, floor - with the infant nearby is not recommended.

From the CDC site:

Have the baby share your room, not your bed. Your baby should not sleep in an adult bed, on a couch, or on a chair alone, with you, or with anyone else.

From the AAP:

The AAP recommends the arrangement of room-sharing without bed-sharing, or having the infant sleep in the parents' room but on a separate sleep surface (crib or similar surface) close to [but not attached to] the parents' bed.

Evidence exists that room sharing without bed sharing decreases the risk of SIDS by as much as 50%, is safer than bed-sharing, or solitary sleeping (in a separate room). In addition, this arrangement is most likely to prevent suffocation, etc., which may occur when the infant is sleeping in the adult bed. Room-sharing without bed-sharing gives the parents close proximity making feeding, comforting, and monitoring of the infant easier.

In a study from Scotland focusing on sharing sleep surfaces, of 123 infants who dies of SIDS between May 1996 and Jan 2000, the highest risk was associated with couch-sharing, then bedsharing. The final recommendation was against bed-sharing for infants <11 weeks of age, and sharing a couch for sleep should be strongly discouraged at any age.

In this article promoting safe bedsharing, the author implies that bedsharing decreased SIDS because breastfeeding reduces SIDS, and bedsharing promotes breastfeeding. The fact is that parents get better sleep if they don't have to get up to breastfeed, which is the factor promoting breastfeeding. The benefit of breastfeeding in the reduction of SIDS is independent of sleep surfaces.

I would love to say sharing a bed is fine and good. But I can't, not yet. I successfully breastfed my children without bedsharing, so I know it's possible.

SIDS and Other Sleep-Related Infant Deaths: Expansion of Recommendations for a Safe Infant Sleeping Environment: Task Force on Sudden Infant Death Syndrome
Bedsharing, roomsharing, and sudden infant death syndrome in Scotland: a case-control study

  • 1
    You are exactly right. Sharing a bed with an infant is void of common sense. 1 - there is nothing to stop them from rolling out of bed. 2 - there is nothing to stop you from rolling onto them. It's like driving without a seat belt - it only takes one accident out of thousands of trips to kill you. And you can't look to other animals for inspiration as some people do. The human infant is incredibly fragile and slow to mature when compared with other mammals. Sharing a room is fine (but I wonder of the long term effects), but sharing a bed is just dumb. May 12, 2015 at 4:10
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    @KurtE.Clothier That's a pretty callous response considering that many parts of the world practice cosleeping and bed sharing as the common, expected way of doing things, including Japan, which usually has some of the lowest infant mortality rates in the world. From what I read, cosleeping in Japan is an all-night thing, too! I'm not appealing to common belief, but I think attacking practitioners of a method you don't agree with is just not okay.
    – user11394
    May 12, 2015 at 19:38
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    I do like the information presented here. It means that our hospital was essentially repeating CDC/APA information, rather than their own personal preferences. (I want to be clear that I don't think there's an agenda, these days. But I do believe that some hospitals used to "push" certain practices, such as formula feeding and face-down sleeping that are now not considered best-practice.) Anyway, I just wish there were studies evaluating these SIDS rates to bedsharing using additional parameters, such as type of bed (firmness), hours spend sharing, and anything else.
    – user11394
    May 12, 2015 at 19:43
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    Absolutely, @CreationEdge - that information is being gathered, I'm sure, but SIDS deaths are not so common that people can start breaking down bed brands yet in a statistically relevant manner. But, just as changes were undertaken when we were very sadly mistaken about prone sleeping, if bedsharing is actually found to be safe in certain circumstances, I think that will come out. Interestingly, a UK study - larger than the Scotland study - put the cutoff at 14 weeks, where the CDC/AAP does not give an age at all. Small steps, but steps nonetheless. May 12, 2015 at 20:24
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    @CreationEdge You're right, I have come off as callous, but it is logical. I'm not saying that bed sharing is a common cause for SIDS, just that its a pointless risk. Room sharing is a beautiful practice. If you like stats, compare those countries with low infant mortality rates with the overall birth rates. I think you will quickly see that those countries with the healthiest babies also have the fewest babies. Also, the babies' health has little to do with co-sleeping, and much to do with wealth and genetics. cia.gov/library/publications/the-world-factbook/rankorder/… May 13, 2015 at 0:07

The short answer is yes, there have been studies showing an increased risk for SIDS even when several of the known risk factors are removed from the equation:

Carpenter et al. (2013) "Bed sharing when parents do not smoke: is there a risk of SIDS? An individual level analysis of five major case–control studies" Key findings:

When the baby is breastfed and under 3 months, there is a fivefold increase in the risk of SIDS when bed sharing with non-smoking parents and the mother has not taken alcohol or drugs.

Smoking, alcohol and drugs greatly increase the risk associated with bed sharing.

A substantial reduction in SIDS rates could be achieved if parents avoided bed sharing.

In other words, they found that bedsharing was associated with an increased risk of SIDS, even when parents didn't smoke or use drugs and the infant was breastfed. The authors acknowledge that they couldn't control for everything, though, and some of the data they used was missing key questions (e.g. some of the studies included didn't ask mothers about whether or not the smoked or used drugs).

A couple things to keep in mind:

  • Research on this topic is tricky because SIDS is not very common. If you start getting very specific about circumstance (infant attributes like pre-term vs. full-term, parent attributes like smoking or drug and alcohol use habits, breastfeeding, bed arrangement, room temperature, etc.), there may only be a handful of cases of infants who have died of SIDS --- not enough to be able to tell statistically whether the risk is increased or not for each subtle change in circumstance.
  • Official guidelines are not evidence --- they're recommendations. Because of the limited evidence, recommendations for parents are generally on the conservative side. There is a clear association between bedsharing and increased SIDS risk, and it's not clear whether that's due only to "incorrect" bedsharing practices, so the official recommendations are to not bedshare at all. That doesn't mean it's categorically unsafe to share a bed with your infant, just that the experts don't feel like they have enough evidence to tell you that it is safe.
  • Many of the studies on this topic are about identifying risk factors for SIDS, such as parent smoking, soft bedding accessories like as pillows or blankets, sleeping on a couch or armchair, etc. There are well-established links between each of these factors and an increased risk of SIDS. That doesn't mean that avoiding those factors completely reduces the risk of SIDS --- SIDS is still not well understood, and there are certainly risk factors that haven't yet been identified. Pay careful attention to the wording in the sources you read --- no one can promise a way to sleep that will make an infant's chance of SIDS 0%. Avoiding known risk factors may make bedsharing safer, but not necessarily safe.
  • SIDS is not the only risk for otherwise healthy infants. Suffocation is an additional risk of bedsharing. Many of the recommendations about how to properly share a bed with an infant (or recommendations to not bedshare at all) are about reducing the risk of nighttime risk in general, not SIDS per se. Some of the studies on this topic lump together all causes of sleep-related infant death, which generally includes SIDS as well as suffocation and strangulation, making it harder to tell what exactly increases the risk for each. If you want a handy summary of evidence on a wide range of sleep-related risk factors for infant death, see the evidence listed in the American Academy of Pediatrics safe sleep guidelines.
  • Bedsharing is quite common outside of a modern, US context. That doesn't necessarily mean it's safe, but it does provide some valuable context for US parents who feel overwhelmed by the heated rhetoric on both sides of the debate here.
  • Question: if there is suffocation of an infant prone in the crib, is it distinguished from SIDS? (Not one caught up in a comforter, etc.) I mean suffocation because of the inability to raise their head off the surface. This would imply that a cause for a SIDS death could never be found, which I am unsure of. Nov 7, 2017 at 13:44
  • My granddaughter stopped breathing for no apparent reason. Luckily, she had had a few episodes of desaturation that brought her to the ED, where she had full blown apnea. She was full term, 3 days old. They did every test in the book (poor baby) with no helpful results. That would have been a true SIDS death, but they don't get to have the workup she did. Nov 7, 2017 at 13:49
  • I'm certainly not an expert on SIDS, but my understanding is that if cause of death can be determined as suffocation, then it's not SIDS (nichd.nih.gov/sts/about/SIDS/Pages/default.aspx). SIDS is when no cause of death can be identified. SUID (sudden unexplained/unexpected infant death) is a broader category often used to encompass both SIDS and suffocation/strangulation. Nov 7, 2017 at 20:18
  • @anongoodnurse Although the cause(s) of SIDS are unknown, I've heard it described as death resulting when an infant's body is unable to overcome a stressor --- the stressor might be a change in body temp, blood pressure, breathing obstruction (like the apnea you mention), etc. This would help explain why low birth weight and premie infants are at higher risk (less ability to regulate their own systems) and why factors like being covered or sleeping on their stomach would increase risk (easier to correct too-high body temp if abdomen and face are exposed vs. pressed against the sleep surface). Nov 7, 2017 at 20:31
  • Thank you, Rose. I was wondering if something had changed recently. Nov 8, 2017 at 1:56

Firstly, there is a distinction that should be made. Co-sleeping is actually the practice of sleeping in the same room with the baby. Bed-sharing is when the baby sleeps in bed next to or between the parents.

Insofar as any studies go, they can't seem to differentiate between sleep-related deaths or suffocation and SIDS/SUID. IMO, the hospital is full of it. This site gives the following reasons NOT to bed-share

Factors that can increase this risk include:

  • a baby sleeping on a couch alone or with a parent
  • a baby sleeping between two parents
  • a mother who smokes
  • parents who are extremely tired
  • a parent who has recently used alcohol or drugs
  • bed-sharing with pillows or bedcovers

Most of these lend themselves to suffocation in some fashion or another.

This article, done by James McKenna and backed by Meredith Small in her book, give plenty of research behind the benefits of bed-sharing and co-sleeping. (more explanation of the links to come)

My Experience

We used both tactics for both of our kiddos. We have something called a co-sleeper that sits at bed-height so mom can pull the kiddo into bed with her to nurse, then set the kiddo back in the co-sleeper to sleep... all so she doesn't have to get out of bed.

After reading up a bit more, this practice seems to be "acceptable" as far as safe sleeping habits and SIDS are concerned.

  • 1
    I think something like the cosleeper you mention or a bed-side bassinet is probably ideal. Do you have any information regarding specific benefits of right-by-the-bed (but not in-the-bed) sleeping arrangements, as opposed to merely in-the-same-room arrangements? (What a hyphen-heavy comment!)
    – user11394
    May 12, 2015 at 19:46
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    Thanks for bringing me back.. I need to update my answer with some links anyhow. I came across quite a few articles showing benefits for near-the-bed (but not in-the-bed) sleeping arrangements. (had to match the heavy-handed-hyphen comment) :) May 12, 2015 at 19:56

There's an important datapoint from Japan which is a developed country where cosleeping is very common. A paper titled Infant Suffocation Incidents Related to Co-Sleeping or Breastfeeding in the Side-Lying Position in Japan explores this subject by first distributing a survey among mothers of infants:

The percent of infants sharing bedding with parents increased significantly with age: 44.9% at 1 month; 56.3% at 4 months; and 76.2% at 10 months. In response to the question of whether co-sleeping or breastfeeding in the side-lying position was practiced regularly, 15.7% of the mothers responded as neither, 28.3% as co-sleeping only, and 56.0% as breastfeeding in the side-lying position. On examining the data based on infant age, 71.3% of mothers of 10-month-old infants were breastfeeding in the side-lying position, which was significantly higher than that for mothers of 1- and 4-month-old infants.

So around 45% of Japanese mothers sleep with babies as young as 1 month old, increasing to 76% by the age of 10 months, which is exactly the dangerous age range according to the CDC. Next they discuss ASSB which a subtype of SIDS:

The incidence of infant ASSB in Japan was 2.5 per 100,000 births in 2016 (Ministry of Internal Affairs and Communications Statistics Bureau 2016). Rates in other countries, such as, 23.0 in the United States in 2015 (Lambert et al. 2018) and 29.0 in New Zealand (The New Zealand Motality Review Group 2016), were higher than the rate in Japan, while the 1.9 in Canada (Gilbert et al. 2012) was similar to Japan. The incidence of ASSB in Japan is lower than in other countries, despite the fact, that co-sleeping is commonly practiced. We believe that this may be attributed to the use of wide and relatively hard bedding (futon) used in Japan. With traditional Japanese bedding, mothers rarely place themselves over infants, while co-sleeping is often performed in a sofa or soft bedding in other countries (Tackett et al. 2010).

So it seems like cosleeping could be very safe if you choose the right sleeping surface. The criteria mentioned in your question similarly refer to hard surfaces being safer. Couches are singled out as particularly unsafe, probably because they're both soft and narrow which is the opposite of Japanese futons which are wide and hard.

It should also be pointed out that Japan has some of the lowest infant mortality rates in the world, so this cannot be attributed to them miscounting SIDS deaths. Finally, remember that preventable SIDS is not particularly common in the first place: CDC statistics show that it went down from 154/100k to 90/100k over 30 years due to various SIDS prevention campaigns. This represents going from a 0.154% chance of a baby dying from SIDS to a 0.09% chance, with a delta of 0.06%. I'll leave it up to each parent to decide if a 0.06% reduction in mortality is important to them.

  • I think one of the practical considerations is that soft bedding (like sofas and soft matresses) can 'dip' in towards the weight. And movement from one side of the bed is transferred to another. (eg adult rolls over, child rolls toward adult). Vs (eg) sleeping on the floor, the movement of the adult does not cause a dip in the surface and the child's surface remains undisturbed. I could sleep on the floor with a baby at arms length and they are effectively still physically isolated on the surface. (equivilent to roomsharing without cosleeping).
    – stan
    Nov 2, 2021 at 9:03
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    As such the statement "cosleeping could be very safe if you choose the right sleeping surface" is key. The japanese study has been used by some people to show that cosleeping in the same bed is OK, but this is a misinterpretation of the literature.
    – stan
    Nov 2, 2021 at 9:07
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    @stan an additional datapoint is that low income families are more prone to SIDS - and low income families also happen to be more likely to have an old mattress that’s lost firmness. Nov 2, 2021 at 9:08
  • Also, poor people in Japan are still going to be sleeping on the floor or on cheap(er) Japanese bedding (that is presumably still firm). I also wonder if there's a genetic part to SIDS where certain people groups are just overall less predisposed in the first place.
    – stan
    Nov 2, 2021 at 9:46
  • @stan It could also be cultural reasons. Sometimes "SIDS death" translates to "mother couldn't handle taking care of her baby, so she suffocated them to death", and it seems reasonable to hypothesise thatl that's something that a lot more likely to happen in a country where abortion is legal when compared with one where it isn't, like Japan.
    – nick012000
    Nov 4, 2021 at 3:46

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