Safe sleep for babies: the evidence-based guidelines

Newborn · Sleep · Reviewed 20 June 2026 · All articles

Every caregiver wants their baby to sleep safely. The guidance that exists today is the result of decades of research into sudden infant death syndrome (SIDS) and sleep-related infant deaths. Following it consistently, for every sleep, can make a meaningful difference. This article walks through the full evidence-based safe sleep framework, explaining the reasoning behind each recommendation so you can understand not just what to do but why it matters.

Why safe sleep guidance exists

SIDS is defined as the sudden, unexplained death of a baby younger than one year of age. It remains one of the leading causes of infant death in the post-neonatal period (one month to one year). Sleep-related infant deaths also include accidental suffocation and entrapment. Together these events are often grouped under the term Sudden Unexpected Infant Death (SUID).

Research over the past 30 years has identified a cluster of modifiable risk factors. Changing caregiver practices in response to this research has produced dramatic reductions in SIDS deaths in many countries. The American Academy of Pediatrics (AAP) published a landmark safe sleep policy in 1992 and has updated it regularly since, most recently in 2022. The NHS in the United Kingdom and Red Nose in Australia publish aligned guidance. The core recommendations are consistent across all three.

Back to sleep: the single most important step

Always place your baby on their back for every sleep, including naps, for the entire first year of life. This is the recommendation with the most robust evidence behind it.

Studies consistently show that the supine (back) sleeping position reduces the risk of SIDS by up to 50 percent compared with prone (tummy) sleeping. The mechanism is not fully understood, but current thinking centres on rebreathing of exhaled carbon dioxide, impaired arousal from sleep, and thermal regulation. Babies placed face-down have a smaller breathing zone and may struggle to lift their head if their airway is partially obstructed.

Side sleeping is not an equivalent alternative. A baby placed on their side can roll onto their tummy, which carries higher risk. Back is the only consistently safe position for unsupervised sleep.

Some caregivers worry that back sleeping increases the risk of choking on spit-up. There is no evidence this is the case. Babies have effective airway-clearing reflexes, and the trachea sits in front of the oesophagus in infants, so the aspiration risk from reflux is very low in the supine position. If your baby has a diagnosed medical condition that your doctor believes warrants a different sleep position, follow your doctor's specific advice.

Firm, flat, and free of hazards: the sleep surface

A baby should sleep on a firm, flat surface designed for infant sleep. Appropriate surfaces include a cot, bassinet, or play yard that meets current safety standards. The surface should be firm enough that it does not conform to the shape of your baby's head when you press it.

Soft mattresses, waterbeds, memory foam toppers, and sofas are not safe for infant sleep. Neither are sitting devices such as bouncers, swings, car seats, or strollers, unless used under direct supervision and only for short periods. The angled or semi-reclined position in these devices can cause a baby's head to fall forward, compressing the airway. If your baby falls asleep in a car seat during travel, move them to a flat surface as soon as it is safe to do so, ideally as soon as you arrive at your destination.

The sleep surface should have a snug-fitting, firm mattress. Gaps between the mattress and the sides of the cot or bassinet should be less than two finger-widths. A mattress cover is fine; additional padding, wedges, or positioners are not recommended.

Room-sharing without bed-sharing

Keeping your baby's sleep surface in your bedroom for at least the first six months, and ideally for the first year, is associated with a reduction in SIDS risk of up to 50 percent. The most likely explanation is that a nearby sleeping adult is more likely to notice and respond if a baby is in distress.

Room-sharing is not the same as bed-sharing. Having your baby in the same bed as you, a partner, or another child significantly increases the risk of accidental suffocation, entrapment against bedding or a sleeping adult, and SIDS. This risk is substantially higher when the sleeping adult has consumed alcohol, sedating medication, or is extremely sleep-deprived. Soft mattresses and heavy bedding increase the risk further.

Safe room-sharing options include a separate cot or bassinet positioned next to the bed, or a bedside sleeper that attaches to the adult bed frame while providing a separate sleep surface with its own firm mattress. These products allow easy feeding access without the risks of bed-sharing.

Keeping the cot clear

The safest cot is an empty one. Remove the following from your baby's sleep environment:

Bumper pads were once thought to prevent injury, but evidence now shows they provide no meaningful protection and can contribute to suffocation and entrapment. They are banned for sale in some jurisdictions and the AAP explicitly recommends against them.

To keep your baby warm without loose bedding, use a fitted sleep sack or wearable blanket in an appropriate tog rating for the room temperature. Dress your baby in one extra layer compared with what you would wear comfortably in the same room.

Temperature and overheating

Overheating is an independent risk factor for SIDS. Keep the room your baby sleeps in at a comfortable temperature, generally between 16 and 20 degrees Celsius (61 to 68 degrees Fahrenheit). You should be comfortable in the room in light clothing.

Signs that a baby is too warm include sweating, damp hair, flushed cheeks, a heat rash, or rapid breathing. Check the back of your baby's neck or their chest rather than their hands or feet, which are normally cooler.

Avoid dressing your baby in a hat for sleep indoors. Babies lose excess heat through their head, and covering it during sleep can contribute to overheating. Hats are appropriate outdoors in cold weather but not for indoor sleep.

Breastfeeding and its protective effect

Breastfeeding is associated with a reduced risk of SIDS. Studies suggest that any amount of breastfeeding provides some protection, and exclusive breastfeeding for the first six months provides the greatest benefit. The mechanism is not completely understood but likely involves immune factors in breast milk, the pattern of arousal in breastfed babies, and the reduced exposure to respiratory pathogens.

If you breastfeed your baby in bed during the night, return them to their own sleep surface before you fall asleep. If you are very tired, consider sitting in a chair rather than lying in bed, as falling asleep while feeding is more likely when lying down.

Dummy or pacifier use

Offering a dummy or pacifier at the start of every sleep, including naps, is associated with a reduced risk of SIDS. The reason is unclear, but one hypothesis is that sucking on a pacifier keeps the airway more open and increases arousal from deep sleep. The protective association is present even if the dummy falls out after the baby is asleep.

If you are breastfeeding, it is generally recommended to wait until breastfeeding is well established, typically around three to four weeks, before introducing a dummy. Do not force the dummy if your baby refuses it. Do not attach it to a cord, ribbon, or clip that could wrap around the neck during sleep. There is no need to use a special orthopaedic or shaped dummy for sleep safety purposes.

Smoke-free environments

Exposure to tobacco smoke, before and after birth, significantly increases the risk of SIDS. This includes both direct smoking near the baby and third-hand smoke (residue on clothing, furniture, and walls). If anyone in the household smokes, keeping the baby away from the areas where smoking occurs, changing clothes before handling the baby, and ideally giving up smoking entirely are all protective steps.

Prenatal exposure to tobacco smoke also increases risk. This is one of several reasons that smoking cessation in pregnancy is strongly recommended.

Supervised tummy time when awake

Tummy time refers to placing your baby on their stomach while they are awake and under direct supervision. It is an important developmental activity that strengthens neck, shoulder, and core muscles needed for rolling, crawling, and sitting. It also reduces the risk of positional plagiocephaly (flat head syndrome), which can develop if a baby spends all waking time on their back.

Start with short sessions of two to three minutes from the first week of life, building gradually to at least 30 minutes of cumulative tummy time per day by three months. Never leave a baby unattended during tummy time, and end the session immediately if the baby falls asleep.

When the guidelines change

The safe sleep recommendations are designed for the period of greatest risk: the first 12 months of life. SIDS risk peaks between two and four months and declines through the first year. After 12 months, risk drops significantly.

Once a baby can roll from back to tummy and tummy to back independently, it is generally safe to let them find their own sleeping position. Continue to place them on their back to start sleep. If they roll onto their tummy overnight, you do not need to reposition them. Ensure the cot remains clear of loose items.

Safe sleep environment checklist

Use this checklist for every sleep:

Guidance from other health authorities

The NHS in the United Kingdom publishes safe sleeping guidance that aligns closely with the AAP framework. The NHS additionally emphasises that the same safe sleep principles apply to premature babies once they are ready for home, and provides guidance on bedside cribs as a way to facilitate room-sharing without bed-sharing. The NHS Lullaby Trust has campaigned on safer sleep for many years and offers detailed resources for caregivers.

Red Nose, the Australian not-for-profit formerly known as SIDS and Kids, produces nationally endorsed safe sleeping guidelines. Their recommendations are consistent with AAP and NHS guidance: back to sleep, safe surface, room-sharing without bed-sharing, smoke-free environment, and breastfeeding where possible. Red Nose also addresses cultural contexts and provides resources in multiple languages.

Across all three frameworks, the message is consistent. The details of implementation, such as specific product certifications, differ by country, so always check that any product you buy for your baby's sleep meets the safety standard current in your country.

Frequently asked questions

Is it safe for my baby to sleep on their side?

No. Side sleeping is not as safe as back sleeping. Babies placed on their side can roll onto their tummy, which increases the risk of SIDS. Always place your baby flat on their back for every sleep until they can roll both ways independently.

When can I add a pillow or blanket to my baby's cot?

Loose bedding, pillows, and soft toys should be kept out of the sleep space for at least the first 12 months. After age one, when a child can roll and reposition themselves, risk drops significantly. Even then, introduce bedding gradually and choose a snug-fitting blanket rather than a large fluffy quilt.

Does room-sharing mean I have to stay in the same room all night?

Room-sharing means having your baby's sleep surface in the same room where you sleep. It does not mean staying awake or sleeping on the sofa. Having your baby close reduces SIDS risk and makes night feeds easier without the risks associated with bed-sharing.

What should I do if my baby always rolls onto their tummy overnight?

Once your baby can roll from back to tummy and tummy to back on their own, it is generally safe to let them stay in the position they choose. Continue to place them on their back to start every sleep. Make sure the cot is free of loose items so there is nothing obstructing their airway if they do roll.