Safe Sleep Guidelines for Babies: What Every UK Parent Needs to Know

Quick answer: Always place your baby on their back for every sleep, in a cot or Moses basket in your room for at least the first 6 months, on a firm, flat mattress with a clear cot — no pillows, bumpers, loose bedding or soft toys under 12 months. Keep the room 16–20°C, stay smoke-free, and never sleep on a sofa or armchair with your baby.

What parents need to know

Sudden infant death syndrome (SIDS) — sometimes called cot death — is every new parent's worst fear. The good news is that following safe sleep guidelines significantly reduces the risk. In the UK, rates of SIDS have fallen dramatically over the past three decades thanks to public health campaigns. This is what the current guidance says.

The core safe sleep rules (NHS & Lullaby Trust)

1. Always place your baby on their back to sleep

Babies should always be placed on their back for every sleep — at night and for naps. Once babies can roll both ways independently (usually around 4–6 months), they can be left in whatever position they roll to, but should always be placed on their back to start.

2. Keep them in your room for the first 6 months

The NHS recommends sharing a room (but not a bed) with your baby for every sleep for at least the first 6 months. The risk of SIDS is lower when your baby sleeps in the same room as you, compared with sleeping alone.

3. Use a firm, flat mattress

Always use a firm, flat, waterproof mattress that fits snugly in the cot with no gaps. The Lullaby Trust recommends a new mattress for each baby where possible. If you use a second-hand mattress, it should have a well-fitting, fully waterproof cover, no rips or tears, no water damage, no sagging, a fire-resistant label, and fit the cot or Moses basket with no gaps.

4. Keep the cot clear

The safest sleep environment for a baby is a bare cot: no pillows, no loose bedding, no bumpers, no soft toys. These items are not safe for babies under 12 months.

A well-fitted sleeping bag is the safest option in place of blankets — it keeps your baby at a consistent temperature without any loose fabric. Choose the right tog for the season.

5. Keep them smoke-free

Never smoke around your baby, and never allow anyone to smoke in your home or car. Exposure to cigarette smoke significantly increases the risk of SIDS. This includes exposure during pregnancy.

6. Avoid overheating

Keep the room temperature between 16–20°C. At this temperature, light bedding or a lightweight, well-fitting baby sleep bag is comfortable, and babies do not need hats indoors. Check the back of their neck (not hands or feet) to gauge temperature — it should feel warm but not hot or sweaty.

7. Never sleep on a sofa or armchair with your baby

Falling asleep on a sofa or armchair while holding your baby is one of the most dangerous sleep situations. If you think you might fall asleep during a night feed, put your baby in their cot first.

What about co-sleeping?

The safest place for your baby to sleep is in a cot or Moses basket in your room. However, the Lullaby Trust recognises that some parents will bed-share and provides guidance to make it as safe as possible.

Co-sleeping is never safe if you or your partner:

• Smoke (even if you don't smoke in bed)
• Have recently consumed alcohol
• Have taken medication or drugs that cause drowsiness
• Are extremely tired

Never bed-share with a premature baby or one born at a low weight.

Dummy use and safe sleep

Research shows that using a dummy (once breastfeeding is established, if applicable) is associated with a reduced risk of SIDS. The NHS does not advise against dummies for this reason. If the dummy falls out during sleep, you do not need to replace it.

The SIDS risk reduces as babies get older

SIDS is more likely to happen in the first 6 months of life, but it can affect babies up to 12 months old, and it can happen at any time a baby is asleep, day or night. If your baby was born early, follow safer sleep advice for a year from their due date rather than the date they were born. Safe sleep remains important throughout the first year.

Frequently asked questions

What temperature should a baby's room be?

Between 16–20°C. Use light bedding or a lightweight, well-fitting baby sleep bag, and check their chest or the back of their neck rather than hands or feet — it should feel warm but not hot or sweaty.