Safe sleep: what actually reduces the risk of SIDS

This is the one topic on this site where the advice is not a range and there is nothing to tailor to your child. The recommendations from the AAP and the NHS are unusually consistent with each other, unusually specific, and worth following exactly rather than adapting.

What follows is what both bodies actually publish, in the order that matters — starting with the small number of things that carry most of the effect.

What SIDS is, and when the risk sits

Sudden infant death syndrome is the sudden, unexpected and unexplained death of an apparently healthy baby. The NHS puts the risk highest in the first six months, and says it can affect babies up to twelve months old.

That shape is why the guidance is front-loaded and why it does not stop at six months. The room-sharing recommendation covers the peak; the sleep-position and empty-cot rules run the whole first year, because the risk does not fall to nothing the day the peak passes.

The three that carry most of the effect

If you remember nothing else from this page, remember these. Everything after them is real but smaller.

• On the back, every sleep. The AAP’s wording is that babies who sleep on their backs are much less likely to die suddenly and unexpectedly than babies who sleep on their stomachs or sides. Naps count. Other people looking after them counts.
• Their own flat, firm, empty surface. A cot, Moses basket, bassinet or travel cot that meets safety standards, with a firm flat mattress and nothing else in it.
• In your room, not your bed, for at least six months. The one recommendation that asks something of the parents rather than of the cot.

Where the baby sleeps

Both bodies describe the same arrangement in slightly different words:

“Feet-to-foot” is the NHS’s term for placing the baby with their feet touching the end of the cot, so they cannot wriggle down under a blanket. If you use a blanket at all it goes no higher than the chest and is tucked in firmly; a baby sleeping bag removes the question entirely.

What goes in the cot, and what does not

The specification is shorter than most parents expect, and the empty version is the correct one:

The AAP names pillows, quilts, blankets, bumper pads and mattress toppers directly. The NHS states the principle behind the list: keep the cot clear of anything that could cover the face and head.

The sofa is the one to remember

Almost every other rule here is about a decision made calmly. This one is about a decision made at four in the morning by someone who has not slept, and it is the reason it deserves its own section rather than a bullet.

The NHS is blunt: do not sleep on a sofa or in an armchair with your baby. The AAP quantifies it at up to 67 times the risk. Both are describing the same situation — a soft surface with gaps and edges, an adult who did not intend to fall asleep, and a baby who cannot move themselves out of trouble.

The practical version:

• Do night feeds in bed rather than on the sofa, and put the baby back in their cot after
• If you might fall asleep feeding, clear your bed of pillows and covers first, so that if it happens the surface is the safer one
• Ask anyone else doing a night feed to follow the same rule

Bed-sharing, stated plainly

The two bodies are not identical here, and it is worth having the actual positions rather than a summary of them.

The AAP asks for the baby’s sleep area to be in your room but not in your bed. The NHS asks for a separate cot or Moses basket in your room, and names circumstances in which bed-sharing must be avoided entirely:

• If your baby was born prematurely, before 37 weeks of pregnancy
• If your baby weighed less than 2.5kg at birth
• If you or your partner smoke
• If you or your partner have drunk alcohol or taken drugs

And in no circumstances on a sofa or in an armchair. If you are making a decision here, make it with your midwife or health visitor rather than from a page — that conversation is specific to your baby and your household, and this one cannot be.

Temperature, smoke and car seats

• 16C to 20C. The NHS gives the range for the room. The AAP puts the same idea in clothing terms: one more layer than you would wear to be comfortable in that room. Overheating is a risk in its own right, so cooler is the safer error.
• No smoke at all. The NHS says do not smoke in pregnancy or around your baby after birth. The AAP extends it explicitly: not anywhere near the baby even if you are outside, and that includes vaping and e-cigarettes.
• Car seats are for travelling. The NHS says not to let your baby stay in one for too long. A baby who falls asleep in the car is fine; a baby left to sleep in the seat once you are home should be moved to a flat surface.

Dummies, breastfeeding and vaccinations

These three appear on the “do” side of the NHS list and in the AAP policy, and they are the ones parents most often do not realise are part of safe sleep at all.

• Breastfeeding, if you can. The AAP’s framing is that the longer you give your baby breast milk, the more protection it gives. The NHS lists it among the things to do. Neither presents it as an obligation, and formula feeding is not a failure of safe sleep.
• A dummy at sleep time. The NHS suggests considering one to settle your baby. The AAP adds that if your baby is breastfed, you wait until breastfeeding is established before offering it. If it falls out after they are asleep, leave it.
• Routine vaccinations, on time. The NHS lists keeping your baby up to date with them as one of the risk-reduction steps.

When they start rolling over

Somewhere in the middle of the first year a baby put down on their back will arrive on their front by themselves. This is the question every parent asks, and the answer is smaller than the worry:

• Keep putting them down on their back. That part does not change.
• Once they can roll both ways on their own, you do not need to spend the night turning them back. Rolling is the strength and head control that tummy time built.
• Keep the cot empty. This matters more once they are moving around it, not less.
• Stop swaddling as soon as they show any sign of rolling.

What this page is not

It is a plain-language summary of two published sets of guidance, not medical advice, and not a substitute for the people who know your baby. If your baby was premature, has a medical condition, has reflux, or if anyone has advised something different from what is here, follow your midwife, health visitor or paediatrician rather than this page.

If your baby is unwell, unusually difficult to wake, breathing oddly, or you are frightened — contact your doctor or emergency services now rather than reading further.