Sleep safety

Safe Sleep for Babies: The Essentials

Based on NHS and Lullaby Trust guidance — updated for 2026

Few things matter more to a new parent than knowing their baby is sleeping safely. The good news is that the most important steps are simple, well-established, and backed by decades of research. This guide pulls together the core safer-sleep advice from the NHS and the Lullaby Trust — two of the most trusted sources on infant sleep safety in the UK.

The aim of this advice is to reduce the risk of sudden infant death syndrome (SIDS), sometimes called cot death. Following it for every sleep — day and night — gives your baby the safest possible start.

The safer sleep basics

The Lullaby Trust advises following these steps for every sleep, day and night, until your baby is 12 months old (or 12 months after their due date for premature or low-birth-weight babies):

• Lie your baby on their back for every sleep — not their front or side.
• Keep the cot clear of anything that isn't essential.
• Use a firm, flat, waterproof mattress in good condition.
• Keep your baby smoke-free, before and after birth.
• Avoid your baby getting too hot.
• Sleep your baby in the same room as you for at least the first six months.

A clear cot is the safest cot

According to the Lullaby Trust, a baby needs just two things in their cot: a firm, flat, waterproof mattress, and lightweight bedding. Everything else should be removed, because items like toys or loose blankets could cover a baby's face and obstruct their breathing.

When preparing your baby's sleep space, the guidance is to leave out:

• Pillows and duvets
• Cot bumpers
• Soft toys and comforters
• Weighted or bulky bedding
• Products designed to keep a baby in one position, such as wedges or straps
• Pods, nests, rolled-up towels, or anything soft placed on top of the mattress

The NHS adds that the mattress should be firm enough that your baby's head doesn't sink in by more than a few millimetres, and that sleeping pods and nests are not advised because of their raised or cushioned areas.

Room temperature

Overheating raises the risk of SIDS, so the Lullaby Trust recommends keeping your baby's room at a comfortable 16–20°C. A simple room thermometer makes this easy to monitor. Dress your baby for the temperature, and remember that bedding or sleepwear that's too warm can cause them to overheat.

Sleeping bags and blankets

The NHS notes that a well-fitting baby sleeping bag can help reduce the risk of SIDS, because it stops a baby wriggling down under loose bedding. The key is fit: it should be snug around the shoulders so there's no risk of the baby's head slipping inside. Sleeping bags carry a tog rating for warmth:

If you use blankets instead, the NHS advises the "feet to foot" approach: lie your baby on their back with their feet near the foot of the cot, so they can't wriggle down under the covers. Tuck the blanket in firmly, no higher than the shoulders, and don't double it over (which can cause overheating). A cellular cotton blanket is ideal, as it keeps warmth in while allowing airflow.

Room sharing

Both sources are clear that the risk of SIDS is lower when your baby sleeps in the same room as you — for all sleeps, day and night, for at least the first six months. This doesn't mean you can never leave the room; it means your baby is safest when you're close by most of the time, so you can keep an eye on them.

Co-sleeping: how to reduce the risk

The NHS is direct that it's always safest for your baby to sleep in their own cot or Moses basket. But it also recognises that bed-sharing sometimes happens, so it's important to know when it's especially dangerous and how to make it safer.

If you do share a bed, the NHS recommends:

• Make sure your baby can't fall out of bed or get trapped between the mattress and wall.
• Keep pillows, sheets, and blankets away from your baby (a baby sleeping bag is safer).
• Don't let other children or pets in the bed at the same time.
• Always put your baby to sleep on their back.

Other things that help

Two further points from the Lullaby Trust are worth knowing. First, breastfeeding — research shows any amount of breastfeeding reduces the risk of SIDS, though if you formula feed and follow the other advice, you can still reduce the risk. Second, consistency matters: babies who are usually slept on their backs but occasionally placed on their fronts are at higher risk, so it helps for everyone who cares for your baby to follow the same routine.

How tracking fits in

Safer sleep is about the environment and routine, not data — but keeping a simple, consistent record of sleeps can help everyone caring for your baby stay on the same page, which is exactly the consistency the guidance encourages. A shared log means a grandparent or nanny can see your baby's routine and follow it the same way you would.