Safe Sleep for Babies

A baby sleeps safest on her back, on a firm flat level surface, in her own cot in your room, with nothing in there but a fitted sheet. That is the whole of it: back, firm, flat, empty, your room, not too warm. It applies to naps as much as to nights, and it has no clever version. Every other page on this site carries two sentences of this one, because timing is the trivial part of a baby's sleep and this is the part that is not.

What follows is each rule with the body that publishes it, in the publisher's own terms and unsoftened. Read the list once; the rest of the page is commentary on it.

The six rules, stated plainly

• Back. For all naps and at night, says the American Academy of Pediatrics. Always, says the NHS.
• Firm, flat, level. A cot, crib, bassinet, Moses basket or play yard meeting safety standards.
• Empty. A fitted sheet and nothing else: no pillows, duvets, cot bumpers, loose blankets, soft toys, pods or nests.
• Your room. Her own cot beside your bed, for every sleep, for at least the first six months.
• Nothing weighted. On her, over her or in the sleep area, at any age.
• Not too warm. The NHS's bedding guidance is written around a room of roughly 16C to 20C.

On her back, for every sleep — including the ones you miss

The AAP wording is back for all naps and at night; the NHS publishes the same instruction under the heading of reducing the risk of sudden infant death syndrome. Note what the phrase covers: this is not a night-time rule with a daytime exception. The twenty minutes in the cot after lunch counts, and so does the nap in a travel cot at somebody else's house.

That second one is the sleep you are not in the room for. Anybody who puts her down needs the same sentence you would use, and the reliable way to hand it over is on paper rather than in a doorway while you look for your keys. The sitter information sheet prints it for that reason: on her back, in her cot, nothing in with her.

The guidance says how a sleep starts. It does not ask you to spend the night turning a baby over, and once she can roll both ways herself, where she travels in an empty cot is hers. You still start every sleep the same way.

The surface: firm, flat, level, fitted sheet

Here the federal wording beats anybody's marketing, because it describes objects rather than a standard. The NICHD's Safe to Sleep guidance asks for a surface that is firm — one that returns to its original shape quickly when you press on it — flat, in the sense of a table rather than a hammock, and level rather than inclined. Covered with a fitted sheet, and nothing else.

Read those three words against the things sold for babies to sleep in and the guidance stops being abstract. A surface that keeps the dent your hand made is not firm. Anything that curves up at the sides, so she settles into the middle, is the hammock shape rather than the table shape. Anything propped, wedged or sold at an angle is inclined rather than level. Each matters for one reason: a soft, curved or tilted surface can leave a baby's head in a position she cannot get out of, and she cannot move herself out of trouble the way you can.

The NHS says it in fewer words — a firm, flat, waterproof mattress in a cot — and both add the caveat about fit: the mattress fills the cot, the sheet fits the mattress.

An empty cot, and the products sold to fill it

Babies go down on their back, on a firm flat mattress, in a cot clear of blankets, pillows, bumpers and soft toys. The NHS list is longer than most people expect: no pillows, duvets, cot bumpers, loose blankets, soft toys, pods or nests — nothing that could cover her face and head. The NICHD's version is a category rather than a list, anything soft, squishy, non-fitted or weighted kept out of the sleep area, and it names a cot holding nothing but a fitted sheet as the safest option there is.

Which brings us to the shelf of products sold as an exception, named here because a parent with one in the cupboard searches for the product rather than for infant sleep product safety. A weighted swaddle, a weighted sleep sack or a weighted blanket for a baby: no publisher this site may stand on recommends one, and two refuse them outright. The NICHD lists anything weighted among the things to keep out of the sleep area, beside the pillows and the bumpers. The AAP says not to use anything weighted, because it can put too much pressure on a baby's chest and lungs. That is the whole published answer, and it is why this site will never suggest one — not for a hard week, not for a nap, not at any age.

Swaddling itself is allowed and has its own rules: only on her back, watched, hips free to bend up and out, and stopped at the first sign of trying to roll — as early as two months in some babies, the AAP notes. The same goes for a sleep sack that compresses the arms, chest and body. The page on when to stop swaddling covers the signal, which is the baby rather than the calendar.

Your room, her cot — and the two chairs

The two get used as if they were one arrangement, and they are not. Room-sharing is her in her own cot or Moses basket, in your room, beside your bed — what the NHS asks for, for every sleep, for at least the first six months. The NICHD reports that room-sharing without bed-sharing may reduce the risk of SIDS by as much as 50% compared with sharing an adult bed or having the baby sleep in a room of her own. That is the strongest single number in this subject, and it is attached to the arrangement almost everybody can manage.

Bed-sharing is her in the adult bed: a different conversation with a different risk profile, worth having with your health visitor or pediatrician about your own household rather than with a web page.

The next sentence is read off the rules above rather than quoted, and worth flagging as such, because none of the wording registered here names a sofa. It does not need to. An adult sofa or armchair is soft rather than firm, curved rather than flat, and full of gaps — it fails every part of the surface rule at once, and it is where a tired parent most often falls asleep holding a baby at four in the morning. If you feed at night and there is any chance of dozing off, do it somewhere you have already made safe.

Warm enough, and no warmer

Overheating is the rule people skip, because a cold-looking baby is easier to imagine than a hot one. The NHS's bedding guidance is built around room temperature: a sleeping bag has to fit well around the shoulders, and its tog number assumes a particular band — 2.5 tog for roughly 16C to 20C, 1.0 tog for 20C to 24C, 0.5 tog for 24C to 27C. A blanket used instead is tucked in firmly, no higher than her shoulders, never doubled over. The AAP adds that swaddling can increase the chance of overheating, which matters most in the weeks when the room is warm and the wrap is habit.

The layer goes on her rather than over her. That is the trick, and it is what makes a well-fitting sleeping bag easier than bedding; the room temperature guide works through the bands and how to check her without waking her.

What changes as she gets stronger

The rules do not move; the cot does. At the first sign of trying to roll, the swaddle stops and her arms come out. When she can pull herself up, the mattress goes to its lowest setting, because a rail that was safe for a baby who could only lie down is one she can now lean over. And the cot has to be genuinely empty rather than mostly empty, because a baby who can move around it will reach whatever is at the far end.

Nothing about the surface relaxes as she grows. The firm flat mattress at eleven months is the one from the first week, and a sleep on you or in a pram — perfectly ordinary — needs an adult awake and watching. The totals by age and wake windows by age pages cover how the day changes shape; none of it changes anything here.

When this is not a setup question

A baby who cannot be settled at all, who is unusually sleepy or hard to rouse, feeding poorly, not gaining weight, breathing in a way that worries you, or whose cry does not sound like her usual one is not a question about a mattress. Nor is a worry that will not go away. That is a call to your pediatrician, GP or health visitor, and a week of written notes — a printed day sheet is enough — makes that conversation shorter than trying to remember it. This page is general information, not medical advice, and it cannot see your baby.