To the Editor: The concerns expressed by Byard and colleagues about “safe-sleeping messages”1 are based on the assumption that bed-sharing (mother and baby sleeping on the same bed surface) is intrinsically dangerous.

While some case–control studies have shown increased mortality for young (but not older) bed-sharing babies of non-smoking mothers, more detailed studies have found excess risk only among parents affected by alcohol, extreme overtiredness, overcrowded housing, or where the sleeping environment was unsuitable, including prone or side sleeping, heavy bedding, waterbeds and sofas.2

Epidemiological studies support the safety of bed-sharing. For example, in Hong Kong and mainland China, bed-sharing is very common, but rates of unexpected infant death are extremely low. This implicates aspects of Western lifestyle and sleeping practices — including the V-shaped pillows (tri-pillows) highlighted by Byard et al, other suffocation and entrapment hazards, and maternal smoking — rather than bed-sharing per se.

Bed-sharing is also the evolutionary norm, providing many opportunities for “mutual regulation” of maternal–infant physiology, including body temperature, sleep cycle and breastfeeding.3 Modern bed-sharing mothers may appreciate the more restful sleep and easier breastfeeding.

Overnight sleep laboratory studies of bed-sharing and solitary-sleeping mother–baby pairs show that bed-sharing mothers are very aware of their baby’s presence, even in deep sleep, and move to avoid overlaying. Bed-sharing babies breastfeed more frequently, but with equivalent total sleep for mother and baby.3 Researchers note the rarity of unsafe prone positions among breastfeeding, bed-sharing infants.3 Other studies have shown increased rates and duration of breastfeeding among bed-sharing mothers and infants.4

For these reasons, bed-sharing has become more popular in Western cultures, with an Australian survey in 2000 finding around 40% of young babies bed-sharing for at least part of the night.5

As with other aspects of care, it is our duty as health professionals to discuss the risks, benefits and practicalities of bed-sharing so that parents can make an informed and safe choice. The Royal Australasian College of Physicians comments, “Co-sleeping or bed-sharing is common and associated with increased breastfeeding rates, longer and more restful sleep, and a protective posture and synchrony of mother with baby . . . All parents should be informed about how to safely co-sleep with their infants”.6

Safe bed-sharing recommendations are available from websites such as the UNICEF UK Baby Friendly Initiative.7

In reply: Our position on bed-sharing was not based on the assumption that it is intrinsically dangerous, but that there is an increased risk of mortality for bed-sharing babies of “parents affected by alcohol, extreme overtiredness, overcrowded housing, or where the sleeping environment was unsuitable” (to quote Buckley). These risk factors were not mentioned by the telephone health advice line quoted in our letter,1 which rather commented that mortality in bed-sharing babies was such a rare event that the caller should not worry about it — little consolation if a fatality occurred.

We agree completely that parents need to be able to “make an informed and safe choice”, but this also requires informing them of potential dangers — which did not happen. Also, we do not agree that mothers are always aware of the presence of their babies, as reports of accidental suffocation during breastfeeding in bed clearly demonstrate.2,3

An informed decision is made when all the information has been provided, not just information that supports a particular point of view. Curiously, Buckley’s final point is to recommend a website for safe bed-sharing advice4 that states quite clearly (with italics): “the safest place for a baby to sleep is in a cot by your bed”. We concur.