Why is sleeping babies on firm surfaces so important and what are the risks if you don’t?

Red Nose Chief Midwife Jane Wiggill helps to shed some light on this important topic so you can make a safe choice when selecting a mattress.


With the array of products available for purchase on the market promising the world, it’s no wonder that parents are confused about where to begin and how to make safe choices.

Many parents believe that creating soft, cosy and nest-like environments for their babies to sleep is the way to ensure comfort, safety and a good night’s sleep for all, but these environments create hazards that have been associated with tragic outcomes.

Babies are built differently to older children and adults

Babies, particularly those under 12 months are vulnerable to sleep-related injury and death due to a variety of different mechanisms. This vulnerability is largely due to the infant’s anatomy at this age. They are born with large, heavy heads, short little necks with weak muscles, smaller more easily compressed airways and reduced temperature control.

Knowing this, it is very important that we don’t introduce further vulnerability to our babies by using items for sleep that are too soft or not flat, as this can increase the risk of sudden unexpected infant death.

Placing babies on unsafe surfaces for sleep encourages chin to chest positioning which directly impacts a baby’s ability to breathe normally. It also increases the risk of suffocation should the face be accidently covered, strangulation and entrapment.

What sleep environment should parents choose?

Red Nose recommends placing your baby to sleep in a cot or a travel cot because all new and pre-loved cots and travel cots sold in Australia must meet the current Australian and New Zealand Standards (AS/NZS 2172) and AS/NZS 2195). Look for a label or sticker that says that it complies with the mandatory standard and when in doubt, ask! Never place your baby in a cot or portable cot that does not meet these standards.

Selecting a safe mattress

A safe mattress is one that is the right size for the cot, is firm, clean and in good condition and is placed flat (not tilted or elevated).

When selecting a mattress, ensure it complies with the size and depth recommended by the manufacturer of the cot. A baby or toddler can get stuck in gaps between a poor fitting mattress and the cot sides. This is especially dangerous if their face is trapped and covered, or their neck is restricted in any way. Make sure there is no more than a 20mm gap between the mattress and the cot sides and ends

Use a firm sleep surface that is compliant with the new AS/NZS Voluntary Standard (AS/NZS 8811.1:2013 Methods of testing infant products – Sleep Surfaces - Test for firmness). For further information about ensuring adequate mattress firmness. Learn more.

A soft mattress or sleeping surface can increase the risk of sudden unexpected infant death if baby rolls over onto the tummy. Remove plastic packaging from the mattress and always make sure that the waterproof mattress protector is strong and a tight fit. Never put soft bedding under the bottom sheet, such as a sheepskin, as this makes the sleeping surface too soft. A pillow, cushion or sofa is not a safe mattress as they are too soft and increase the risk of sudden unexpected infant death.

In portable or ‘porta’ cots use the firm, clean and well-fitting mattress that is supplied with the portable cot. Don’t add additional padding under or over the mattress or an additional mattress.

To learn more about baby safety visit our Advice Hub

Last modified: 25/1/22