One rule every infant carer likely knows is that it’s safest for babies to sleep on their backs, not on 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 carers with questions. For example, if you have a baby who naturally rolls onto their side or just really prefers sleeping on their side, is that ever OK? When can babies sleep on their side without it being unsafe?
The problem with side sleeping is that it makes it more likely for babies to roll onto their bellies. While SIDS tends to be associated with sleeping in a prone position, babies who slept on their sides have also succumbed to SIDS.
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 tips and advice on when babies can sleep on their side safely.
Why can’t babies sleep on their side?
Experts generally agree that babies should never be deliberately put to sleep on their sides. The main reasoning behind this recommendation is the risk of the sudden and unexpected death of an infant, whether it be from SIDS, accidental strangulation or suffocation during sleep or unknown causes. These result in the tragic loss of hundreds of babies each year.
Stomach sleeping is particularly concerning and is a top risk factor for SIDS and other instances of sudden unexpected deaths of infants. 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 who are put to sleep on their sides and then turn onto their stomachs face a higher risk of SIDS than babies who are routinely placed on their stomachs for sleep.
The key driver in reducing deaths from SIDS has been placing infants on their backs to go to sleep. 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 sleep on their backs. The rates of SIDS cases fell by over 50% in the UK between 1993 and 2014.
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, advice from the NHS says you can keep babies safe during sleep by adopting the following practices:
- Choosing a firm, flat, waterproof mattress or sleep surface for the baby
- Keeping the cot clear of loose objects, pillows, toys, blankets and cot bumpers
- Preventing the baby from overheating.
The NHS also recommends having the baby sleep in a cot in the same room as you for their first six months at a minimum so you are aware of their movements, breathing and needs.
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 carers to wonder if it’s necessary to move them onto their backs and risk waking them.
NHS advice suggests that it’s not usually something to worry about if babies roll onto their sides in their sleep themselves when they are able to. Most babies develop the ability to roll over at about 4 months old. According to official guidance, the risk of SIDS is at its highest by far when babies are younger than this. Beyond 4 months, they are out of the highest-risk period and can usually continue sleeping on their side if they have naturally made their way there. The main thing is to always place them on their backs in the first place, and to make sure their surroundings do not pose any risks.
Is there a way to prevent side sleeping for babies?
Some products, such as wedges and sleep positioners, claim to prevent rolling over or side sleeping, but these are considered unsafe. You can’t prevent a baby from rolling over onto their side once they are able to, and this kind of equipment puts babies at greater risk of suffocating or becoming caught underneath.
Expert advice similarly warns that parents and carers should not use sleep positioners, nests, wedges, 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 happening. You needn’t overthink this, and concentrating on 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? According to expert advice, babies should not be put to sleep on their sides until they are at least a year old. The danger of succumbing to SIDS is much lower for babies once they reach the one-year mark. This means that from this point on, it can be safer to allow them to sleep on their sides.
Of course, every baby is different. Certain conditions or health factors may make side sleeping unsafe 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 a baby’s sleep. This can seem stressful, but it’s important to remember that they are all in the name of keeping babies healthy and safe.
Babies who roll onto their sides or prefer sleeping on their sides may be able to stay in that position if they’re rolling over on their own (which happens at around the age of 4 months) or if they’re at least 1 year old. But it’s recommended that infants be put to sleep on their backs — on a firm, 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, speak to your child’s GP.
