One rule every infant caregiver likely knows is that it’s safest for babies to sleep on their backs, not their stomachs or sides. On the surface, this sounds simple enough — back-sleeping is associated with a lower risk of Sudden Infant Death Syndrome (SIDS). But the rule can also leave parents and caregivers with questions. For example, if you have a baby who naturally rolls onto their side or just really prefers to sleep on their side, is that ever OK? When can babies sleep on their side without being unsafe?
The problem with side sleeping is that it comes with a higher risk of the baby rolling onto the belly. Even though most infants who died of SIDS are found to have slept in a belly or prone position, it has also occurred in infants who slept on their side.
The problem with side sleeping is that the “side position is unstable: a baby is likely to roll into the high risk tummy position, placing the baby at nine times the risk of SUDI.” That’s the advice from Red Nose, Australia’s leading authority on safe sleep and safer pregnancy advice.
Though back sleeping is safest for babies, experts agree that there are caveats, and that side sleeping may not always be a hard “no”, depending on the circumstances and the age of the baby. Let’s take a closer look at the issue of side sleeping, including expert tips and advice on when babies can sleep on their side safely.
Why can’t babies sleep on their side?
The sources we consulted all agree that babies should never be deliberately put to sleep on their sides. The main reasoning behind this recommendation is the risk of Sudden Unexpected Death in Infancy (SUDI), which results in the tragic deaths of about 100 babies per year in Australia. SUDI is an umbrella term that includes infant deaths from SIDS, unknown causes and accidental strangulation or suffocation during sleep.
Stomach sleeping is particularly concerning and is a top risk factor for SIDS and SUDI. This is because stomach sleeping can increase a baby’s risk of:
- Becoming overheated.
- Breathing in exhaled air, which can increase carbon dioxide in the baby’s body.
- Experiencing changes in heart and lung function, which can limit oxygen reaching the brain.
Side sleeping is problematic, too, because it increases the chances that a baby will turn onto their stomach. There’s also evidence that side sleeping in and of itself is a risk factor for SIDS. Research has found that babies put to sleep on their sides, who then turn onto their stomachs, face a higher risk of SIDS than babies who are routinely placed on their stomachs for sleep.
Ensuring that babies sleep on their backs has been the single most important factor in reducing infant deaths. Back in the early 1990s, when physicians discovered that babies who slept on their backs were much less likely to die of SIDS, they began recommending that all babies be put to sleep on their backs. In 1990, for instance, around 500 Australian babies were lost to SIDS — now it is little over 100.
What is the safest way for babies to sleep?
Putting your baby to sleep on their back is one of the most important ways to keep them healthy and safe during the newborn period, but safe sleep isn’t only about sleep position. It’s also about creating an overall safe sleep environment for your little one.
In addition to putting babies to sleep on their backs, the New South Wales Government’s Life Events information service says you can keep babies safe during sleep by adopting the following practices:
- Putting your baby to sleep in a cot
- Avoiding the use of soft toys, pillows, blankets and cot bumpers
- Using a mattress that fits well in the cot so there are no gaps
- Wrapping or swaddling your baby
- Not letting your baby get too hot or cold
And while you shouldn’t sleep with a baby in bed, the Australian Government’s Pregnancy, Birth and Baby advice service recommends sharing a room with the baby for the first six to 12 months.
What if a baby rolls onto their side while asleep?
It’s clear that you shouldn’t put babies to sleep on their side, but what if they roll onto their side on their own? This definitely happens to many babies, leaving parents and caregivers to wonder if it’s necessary to move them onto their backs and risk waking them.
The Raising Children Network says once your baby can roll over (around four to six months), you should still put them down to sleep on their back, but you can also let them choose their own sleeping position. Babies younger than four months are at a much higher risk of sleep-related infant death. In fact, the risk is five to 10 times higher for babies under four months. If your baby hasn’t started rolling over yet but somehow manages to get onto their side, it’s OK to leave them sleeping. You just need to make sure you continue to put them to sleep on their backs and that the rest of their sleep environment is safe.
Is there a way to prevent side sleeping for babies?
Some products, such as wedges and sleep positioners, claim to prevent rolling or side-sleeping, but these are unsafe. You can’t prevent a baby from rolling over onto their side once they are able to and, according to Red Nose Australia, “Some of these products are made with soft, compressible materials, which might increase the risk of suffocation.”
Product Safety Australia similarly warns that parents and caregivers should not use sleep positioners, nests, wedges, weighted blankets, anti-roll products or other devices marketed to keep babies in a certain position during sleep.
If a baby frequently rolls onto their side, you might be wondering if there’s anything you can do to prevent it from happening. But you don’t need to overthink this: simply putting the baby down safely — on their back — is the best way to avoid any issues.
When can babies safely sleep on their side?
When can you finally let a baby freely sleep on their side? The risk of SIDS decreases significantly at 12 months, and it is OK for baby to sleep in a side position from this point on.
This means that once a child is over 12 months old, they should be able to fall asleep on their side or even be placed to sleep in this position. This aligns with guidance from all state and federal health authorities which states that babies should be placed to sleep on their back for both naps and night sleep during the first year (12 months) of life.
Of course, every baby is different. Certain conditions or health factors may make side sleeping unsafe even beyond 12 months of age. Safe sleep guidance should always be verified with a child’s doctor.
The bottom line
There are a lot of rules and guidelines when it comes to baby sleep. This can seem stressful, but it’s important to remember they are all in the name of keeping babies healthy and safe.
Babies who roll onto their sides or prefer to sleep on their sides may be able to stay in that position if they’re rolling on their own (which happens around the age of four months) or if they’re at least one year old. However, it’s recommended that infants be put to sleep on their backs, on a firm and clear surface, every single time.
Always talk to a doctor before making changes to a baby’s sleep environment. If you have questions about side sleeping or safe sleep in general, reach out to your baby’s paediatrician.