While deaths from Sudden Unexpected Death in Infancy (Sudi) have reduced dramatically over 20 years, more could be avoided if those caring for babies ensured babies always slept in a safe place, Nelson paediatrician Dr Nick Baker says.
More could be done to educate parents about how to ensure every sleep was as safe as it could be, he said.
Dr Baker, who is also the chairman of the New Zealand Child and Youth Mortality Review Committee, said some people were still getting mixed messages about sleeping and some were unaware that pillows could be fatal to a baby.
It was not a matter of telling people what to do, but ensuring that their decisions about where babies slept were informed.
Typical circumstances of accidental suffocation included wedging or overlying.
Wedging could occur when a baby moved into a space such as that between a wall and a mattress, between mattresses or became trapped in a faulty cot or on couch cushions.
Overlaying need not need to involve the whole body of another person over the baby - it could be a limb, or breast or small sibling.
Asked if an obese mother sleeping with a baby was a particular risk, Dr Baker said anything which might reduce someone's awareness was of concern, and it was common for overweight people to be very deep sleepers.
The use of alcohol or drugs by those sleeping with a baby also increased the risk to the baby.
The "bottom line" was not to put "babies in harm's way", he said.
Families should be told there were definite risks while co-sleeping for all infants, especially under 3 months of age and greater risks for more vulnerable infants.
Babies sleeping with older siblings was not uncommon, but it had to be realised that a 2 or 3-year-old was very mobile in sleep and could easily "end up on top of baby's head".
Much emphasis was given by district health boards to ensure when new babies left hospital they had a safe place to travel home.
"We need to put just as much effort into making sure they have a safe place to sleep."
Annual deaths for Sudi had dropped to about 60 a year from 200, but New Zealand's rate among industrialised nations was still the highest.
In Sweden and Iceland the rate was about a 20th of the New Zealand rate, he said.
In a recent article in the New Zealand Medical Journal, Dr Baker said the burden of the problem fell disproportionately in the Maori community and among families living in deprived circumstances.
He praised the initiative in Christchurch to issue babies with pepi pods - specially designed easily portable firm sleeping pods - to ensure babies had safe sleeping places during a time of upheaval, but which allowed them to remain near parents.
He said he thought that lives would have been saved by this.
Even allowing a baby to sleep alone in a bed designed for an adult there was at least a 20-fold increased risk of suffocation compared with an infant in a cot, he said.
Faulty cots or those with ill-fitting mattresses were also problematic.
Dr Baker said health professionals had an "absolute duty" to ensure families were never again left with "stunned amazement" if their infant died in an unsafe sleeping place.
Sudi
• Ideal sleeping spaces for babies:
• Are smoke-free.
• A place where they can sleep on their backs.
• Provide a firm surface.
• Do not have pillows, soft surfaces, gaps or cords.
• Keep their faces clear at all times.
• Do not allow them to be trapped.
• Ensure that nothing can accidentally move to cover their face or flex their neck.
• Do not allow the baby to overheat.
• Do not involve sharing with adults who are intoxicated or very tired.
• Should be designed for infant sleep (not couches or adult beds).
• Do not involve sharing with an adult or child, particularly under the age of 3 months.