This week a new study was published in the BMJ which gave rise to headlines regarding the dangers of sharing a bed with your baby: Bed sharing when parents do not smoke: is there a risk of SIDS? An individual level analysis of five major case–control studies.
The authors of this report combined the results of five studies done in different countries between 1987 and 1998. The amalgamation of these studies gave a sample size of 1472 babies who died, and a control group of 4679 babies who did not. Each individual study compares the conditions of the babies in the two groups. However the individual studies did not look at the same risk factors. The authors were able to draw out some significant factors, and show the level of risk for babies who were in their parents’ bed, compared with babies who were in their own bed in their parents’ room. The risk factors examined are whether the baby was breastfed or bottlefed, whether either parent smoked, the position the baby was put down in (front or back), whether the mother had had alcohol or illegal drugs in the previous 24 hours.
The report concludes that the lowest risk of cot death is where a breastfed baby of a non-smoking, non-drinking mother sleeps on his/her back in the parents’ room, but not in the bed. That is, in the absence of any of the risk factors studied here, the risk of cot death is 0.08 per 1,000 live births. When a baby with the same conditions shares his/her mother’s bed, the risk increases to 0.23 per 1,000 live births. This was reported in the popular press as “FIVE TIMES MORE LIKELY!!”
The Telegraph headline claims that this report “sheds new light on cot deaths”, which is interesting given that the studies in the meta-analysis are more than 15 years old. There are more recent studies the results of which do not support these conclusions. A number of known risk factors are missing from the meta-analysis, including smoking during pregnancy, use of legal drugs such as the strong painkillers often used in the early postnatal period, parental obesity, paternal alcohol use, prematurity, the conditions of the bed itself (was the baby between the parents or on mum’s side, was the baby on a pillow, were other siblings or pets also in the bed, etc). The authors are open about the fact that some of the drug/alcohol data was missing, so they “imputed” this. A cynical mind would define the verb “to impute” as meaning “to make stuff up.”
A huge flaw in the report, and in most studies of cot death risk, is the definition of a breastfed baby. In most cases “breastfed” includes partly formula fed babies. We know how fast the rate of breastfeeding falls in the UK (79% at five days; 58% at six weeks), so it is understandably hard to generate an appropriately large sample of exclusively breastfed babies. However all studies show a lower risk for breastfed babies compared with formula fed babies, therefore it makes sense to me that partly breastfed babies should be either a separate data set, or included with the formula fed babies. The report also implies that while bedsharing is associated with longer duration of breastfeeding, the risk of bedsharing is not cancelled out by breastfeeding and therefore this cannot be considered as a reasonable justification of bedsharing. This overlooks the fact that cot death is not the only thing that breastfeeding protects babies – and mothers – against. The long-term risks of not breastfeeding are well-documented, and may, for some parents, outweigh the 0.23 per 1,0000 risk of bedsharing.
Of course the media is generally more reticent in reporting the apparent protective effect of breastfeeding, lest we make mothers feel guilty. This delicacy does not appear to apply to parents who choose to share a bed with their baby* who appear to make up a similarly large group to the formula feeding parents. (This of course implies that huge numbers of bedsharing parents are also formula feeding parents, which is the higher risk). So here is the point at which I climb, with a sigh, on to my usual hobby horse of WHY ARE WE TRYING TO SET PARENTS ONE AGAINST ANOTHER? What is the use of demonising parenting decisions, banning common behaviours rather than informing about risk and how to reduce it?
Whether you choose to sleep with your baby in your bed, beside your bed, or in another room, it is important to be aware of safety guidelines. If you think you will NEVER sleep with your baby, it is still important to be aware of safety guidelines, as for a lot of parents this is not a planned thing, and that in itself increases the risk. Let us not make bedsharing a taboo subject, or a polarising argument. Let us accept that we all parent in different ways, and we are entitled to be well-informed, rather than dictated to, about risk.
*How many parents share a bed with their baby?
Data from both studies found that almost half of all neonates bed-shared at some time with their parents (local = 47%, 95% CI 41 to 54; national = 46%, 95% CI 34 to 58), and on any one night in the first month over a quarter of parents slept with their baby (local = 27%, 95% CI 22 to 33; national = 30%, 95% CI 20 to 42). Bed-sharing was not related to younger mothers, single mothers, or larger families, and was not more common in the colder months, at weekends, or among the more socially deprived families; in fact bed-sharing was more common among the least deprived in the first months of life. Breast feeding was strongly associated with bed-sharing, both at birth and at 3 months. Bed-sharing prevalence was uniform with infant age from 3 to 12 months; on any one night over a fifth of parents (national = 21%, 95% CI 18 to 24) slept with their infants.
