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News: Bed-sharing raises cot death risk fivefold

Screams the BBC headline today, followed by "The risk applies even if parents avoid tobacco, alcohol and drugs - other factors firmly linked to cot deaths."

Several organisations have responded with statements highlighting why 15-26 year old data, collected in different countries at different time points, using different methods and definitions for data collection might not be the most reliable of evidence.  The first is a report from the fantabulous folk at ISIS, big thanks to them as they've saved me a lot of blogging time!

There's also one from UNICEF, and another from the NCT.

I think Isis cover the science side well in terms of picking apart why we shouldn't discount all the existing, contradictory studies because of this one piece, so here's a few thoughts of mine that sprang to mind:

Nestled within the study, researchers note:
  • "Bottle feeding increases the risk of SIDS. When analysed as a single factor, the OR for bottle feeding is 2.9 (2.5 to 3.3), the multivariate AOR is 1.5 (1.2 to 1.8)."
But this didn't seem to make the headlines...Funny that...

Perhaps this is why the comments some have shared from parenting forums today, include those from  parents who cannot understand why anyone would consider bedsharing given the risks, whilst themselves exclusively bottle feeding?

On the subject of bedsharing and breastfeeding the researchers state:
"When the baby is breastfed and under 3 months, there is a fivefold increase in the risk of SIDS"
Cripes right!  I'm sure to make such a sweeping claim the authors must have carefully considered data surrounding breastfed infants?  

Let's check out their criteria!
"Breastfed: infant was being partially or completely breastfed at the time of death or interview." 
Meaning if the baby goes to the breast once per day for 5 mins he is, for the purpose of this study considered "breastfed", despite the fact other studies have suggested a dose related risk.  Should exclusive v mix fed be considered separately, it's entirely feasible that we would note even more statistically dramatic differences in outcome as have been highlighted in other studies.
  • Suffocation or SIDS?  It seems researchers included cases where suffocation occurred, because the characteristics are similar.  Yet despite this there is no consideration for other pretty significant known risk factors:
  • No mention of bedding or other variables...
Did the babies usually co-sleep and so the sleep space had been altered accordingly (removing pillows/preventing baby becoming wedged etc) or had the parent(s) brought the baby into bed occasionally or even for the first time that night?  Could any of the babies have been unwell during the day which in turn could have led to bedsharing when they typically didn't?

Were the babies swaddled?

What about room temps (which can vary massively depending upon location and are another known risk factor)   

What types of bedding were involved?

Without considering all of the above, the guideline is simply to cot sleep?  Despite the fact babies die in cots too.

As I was pondering how to conclude this post, this must read response paper plopped into my inbox - which neatly sums up all there really is to say on the subject.

So I'm going to close with some personal thoughts about sleep, based on my own two (ie entirely anecdotal).  

With number one we didn't co-sleep, we had a moses basket and then a cot.  I was exhausted from getting up frequently to feed (as newborns typically do so often!) and I nearly fell asleep numerous times during night feeds; something we know is a significant risk factor for SIDS.

Even with a moses basket you have to sit up, lean to reach them and then get up again when the feed has finished.  My daughter was windy and so often after getting settled we would have to "rinse and repeat" numerous times - all with that super responsive startle reflex young babies have when they are being lowered, arms flailing out to grasp as they panic they are being dropped.

If mum has to return to work you can see how easily the appeal of a bottle someone else can give, sleep training and a sleep "routine" become so normalised.  Indeed mothers who bed-share tend to breastfeed longer and maintain exclusive breastfeeding longer than those who do not.1–3  Therefore surely studies need to offset the increased rates of formula feeding, and thus increased risk of SIDS that may follow any recommendation that all should use cots?

The second time around we were more aware of the works of people like Mckenna, has considered different "cultural norms" and so we used a combination of a bedside cot and bed sharing between myself and the cot.  We ensured there were no gaps he could get wedged in, or soft bedding within his reach.

Night feeds were easy, no crying as I would rouse as he did.  No sitting up and getting in and out of bed meant neither of us woke fully, and thus needed much less settling (plus parents know young babies settle so much easier next to mum!).  Regardless of how many nightfeeds he had I was never shattered  - making continued breastfeeding with unrestricted night feeds easy despite returning to work part time, something UNICEF also acknowledge.

The unrestricted part may indeed be important as we also know from studies considering pacifier use that sucking to sleep can reduce SIDS risk if the pacifier is used at every sleep, indeed the Academy of Breastfeeding Medicine say:
"As exclusively breastfed infants feed frequently through the night, breastfeeding is thought to reduce SIDS by the same proposed mechanism as supine sleep and pacifiers, namely less deep sleep and frequent brief awakenings. Breastfed babies do not need artificial pacifiers to get stimulation since they already have the protective effect of suckling during the night."
A study promoted by FSID to support pacifier use also suggested increased risk of SIDS if an infant normally has a pacifier, but does not have one at the last sleep. The same may therefore potentially be true of "sleep training" a breastfed infant, if the techniques include "self soothing" or "teaching" the baby to sleep without sucking for fear of "bad habits".

Lastly we never needed to try and hinder his natural reflexes with techniques such as swaddling (something linked to increased respiratory rate 4–5).

None of this is considered in a study that didn't even separate out those exclusive breastfeeding from those having "some breastmilk", before making sweeping recommendations all babies should sleep alone.  Seriously?

  1. Ball HL 2003, Breastfeeding, bed sharing and infant sleep. Birth. 30(3): 181-188.
  2. Blair PS, Heron J, Fleming PH 2010, Relationship between bed sharing and breastfeeding: Longitudinal, population-based analysis Pediatrics 126(5): e1119-e1126.
  3. McCoy RC, Hunt CE, Lesko SM, Vezina R, Corwin MJ, Willinger M, Hoffman HJ, Mitchell AA 2004, Frequency of bed sharing and its relationship to breastfeeding Dev Behav Pediatr. 2004, 25(3): 141-14.
  4. 11. Gerard CM, Harris KA, Thach BTT. Physiologic Studies in Swaddling: An ancient childcare practice, which may promote the supine for infant sleep. J Pediatr. 2002;141:398–404. [PubMed]
  5. Narangerel G, Pollock J, Manaseki-Holland S, Henderson J. The effects of swaddling on oxygen saturation and respiratory rate of healthy infants in Mongolia. Acta Paediatrica. 2007;96:261–5.


  1. This flawed research makes me very angry. It does no good but potentially a lot of harm. Like you, I fell asleep with my first while feeding and didn't know about the risks of that. Lots of sleeping in armchairs and almost dropping of baby. With my second, I spotted her life threatening illness because she was right next to me in my bed, I would most likely have missed it if she'd been in her cot. Does the study account for babies whose illness was spotted and treated in time? I know this is anecdotal, but that question is not asked, and it has an impact. If we only look at SIDS, we only get stats for that, if we look at survival rates for Meningitis and Scepticimia, we may have children who did not die or do not have severe after effects because they bedshared.

  2. I've already shared two articles about this tonight and I wish I'd seen this beforehand as I don't feel I can share yet another one - well maybe tomorrow - but I agree this new research makes me really angry as well. I've been there, trying to stay awake all night with a baby who would feed for two hours or more and startled at the slightest movement to put her back to bed. It was hell, and once or twice I terrified myself by accidentally falling asleep while sitting up. That scenario is so much more dangerous and sadly as a result of this research it could become more common.

  3. Fab post.

    I fell asleep once while feeding my 2 week old. I was sitting on the edge of the bed, breastfeeding, and the next thing I know, I'm back in bed, under the covers. I have no recollection of putting the baby back into his cot at all. It terrified me. Actually getting up and making him a bottle made me 'wake up' more, I was less likely to just put him down and roll back over to sleep, so I did that for the next few weeks.
    In the end (at about 3 months, when BF was finally well established) we ended up putting a single bed in the baby's room. This bed was essentially a mattress on the floor, no pillows and one blanket. By spending our co-sleeping time in this bed, and not the 'marital' bed, I felt a lot more confident about col-sleeping, and ended up getting loads more sleep than I did by either bottle-feeding or breastfeeding with the baby sleeping in his own cot.

  4. Thank you so much for this post. I was absolutely LIVID when my husband sent me a link to this article in the Guardian, and I am very happy to see that you've raised the same points about the 'breastfed' definition in the study that I noticed when I downloaded it. I am not a statistician, and I don't understand the point about missing data being imputed. Could you possibly comment about that? Is the imputed data significant, and does it cast further doubt on this 'study'?

  5. This made me very angry, as did the subsequent response from unhelpful family members.
    Imputed means that the data was missing or incomplete, so was effectively guessed. Difficult to do with any degree of confidence I would have thought, especially given that the studies included were from a range of countries and therefore cultures...

  6. There are some excellent critiques of this paper in the comments, especially the one called "More questions than answers" from researchers at MIPH, University of Heidelberg.

    In my opinion the three biggest faults they highlight are
    1. The definition of breastfeeding includes those who are mixed feeding. In my experience many people who mix-feed use a bottle for the last feed or during the night to help the baby sleep better - so these should definitely not be lumped in with the exclusive breastfeeding group.
    2. There is no distinction between planned and non-planned co-sleeping. A baby who is a bit off-colour might end up co-sleeping when they don't normally, and would surely be at higher risk of SIDS. Planned co-sleeping is also more likely to have the right sort of bedding etc.
    3. 60% of the data has no info on drug or alcohol use. The authors assign the missing data randomly, which would be valid if the missing data were from the same group as the complete data. However, the missing groups are from different cultures and possibly different socio-economic backgrounds (the MIPH guys explain it better). Therefore it is quite possible that this method isn't valid. For example, if the missing data were from a culture with high alcohol consumption, but were filled in with random data matching a low alcohol culture, then they would be underestimating the effect of alcohol. As alcohol is far far more risky for SIDS than the effects they find for co-sleepig, a small mismatch of alcohol data could completely wipe out their result.

  7. The link to the comments is here


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