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 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 the first 6 months. Room sharing reduces the risk of SIDS by up to 50%.

3. Use a firm, flat mattress

Always use a firm, flat, waterproof mattress that fits snugly in the cot with no gaps. A second-hand mattress should only be used if it is dry, clean, and originally from a smoke-free home.

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. A good rule of thumb: dress your baby in one more layer than you would wear yourself in the same room. 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 most common in babies under 6 months, with the highest risk between 2 and 4 months. Risk reduces significantly after 6 months and is rare after 12 months. Safe sleep remains important throughout the first year.

Frequently asked questions

What temperature should a baby's room be?

Between 16–20°C. Dress your baby in one more layer than you would wear yourself in the same room, and check the back of their neck rather than hands or feet — it should feel warm but not hot or sweaty.

When can my baby sleep on their front?

Once babies can roll both ways independently, usually around 4–6 months, they can be left in whatever position they roll to. They should still always be placed on their back to start every sleep.

When is the risk of SIDS highest?

SIDS is most common in babies under 6 months, with the highest risk between 2 and 4 months. Risk reduces significantly after 6 months and is rare after 12 months, but safe sleep matters throughout the first year.

Are dummies safe for sleep?

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