Infant Safety and SIDS

A baby asleep in a bedside crib attached to the parents' bed at night, with a lit city view through the window

I put off writing about this for a long time. It was the subject that frightened me most in Shan's first year, and I didn't trust myself to be calm about it, which is a poor reason to leave something unwritten when other people are frightened of it too. Everything clinical comes from the Lullaby Trust and from the American Academy of Pediatrics task force, whose 2022 recommendations are the current reference. I'm a mother rather than a clinician, which on this subject counts for more than it does anywhere else I write.

Here's the part I'd have wanted first. The risk is low, it has fallen enormously, and almost everything that reduces it further is free.

What's known

Sudden infant death syndrome is the sudden, unexplained death of a baby under one in whom no cause is found after investigation. The word to sit with is unexplained. Nobody can tell you why it happens to one baby and not another, and any source that claims otherwise is overreaching. The prevailing model is that it takes three things arriving together, a baby who's vulnerable in some way nobody can identify in advance, a critical window of development in the first six months, and an external stressor, most often something about the sleep environment, and it's the third of those that anybody can control, which is the whole of what the guidance is aimed at. The reason to take it seriously is that it worked. When the Back to Sleep campaign began in 1994 and parents across whole countries moved babies onto their backs, rates fell by roughly half. One of the clearest results in modern public health, from a change that costs nothing.

Risk is highest between two and four months and drops sharply after six.

The things that reduce risk

This is the list. It's short.

On the back, for every single sleep, including naps and including at other people's houses. This is the largest single factor.
In her own clear, flat, firm sleep space, with a firm mattress and a fitted sheet and nothing else in it. No pillows, no duvets, no bumpers, no pods, no nests, no soft toys for the first year.
In your room for the first six months, day and night. Room-sharing without bed-sharing is strongly protective, and it's the recommendation people most often abandon at four months.
Smoke-free, before birth and after. Smoking in pregnancy and exposure afterwards are among the strongest modifiable risk factors there are.
Never on a sofa or in an armchair with a baby. This is the most dangerous place an adult and a baby can fall asleep together, and plan around at three in the morning when you can feel yourself going.
Not overheated. Keep her feet to the foot of the cot, tuck any blanket no higher than her shoulders, and use one layer fewer when you're unsure. Check the back of her neck or her chest for warmth.
Breastfeeding, where it is possible for you, reduces the risk. So is a dummy at sleep times once feeding is established, which is a curious finding and a consistent one.
Immunisations on schedule, which lower the risk and not, as some corners of the internet insist, the reverse.

The sleep rules in practice

Sleeping in a car seat, a bouncer, a swing or a sling isn't the same as sleeping flat, because a young baby's head can fall forward far enough to compromise her airway and she has very little ability to correct it.

Babies fall asleep in all of those things constantly, and that isn't the problem. The rule is that a baby who has fallen asleep in one gets moved to a flat surface as soon as it's practical, and that nothing on wheels or on an incline is used as a place to leave her sleeping, which includes leaving a car seat indoors after a journey, the version almost everybody has done at least once. I did it more than once.

If you might share a bed

Here's how I'd want it handled for me. Advice that pretends nobody bed-shares helps no one.

The formal position is that the safest place for a baby to sleep is in her own cot in your room, and I'm not going to soften that. What's also true is that a large number of parents end up sharing a bed at some point, usually unplanned, usually at the exact moment they're least able to make a good decision, so know in advance where the absolute lines are.

Bed-sharing must never happen at all if any of the following apply. These aren't cautions. They're exclusions:

Anybody in the bed has been drinking, has taken drugs, or is on medication that causes drowsiness.
Anybody in the bed smokes, or the mother smoked during pregnancy.
The baby was premature or of low birth weight.
Anybody is unusually exhausted, which requires a level of honesty with yourself that is hard at four in the morning.

Where none of those apply and it happens anyway, the arrangement is what counts: a firm flat mattress, no pillows or duvets near her, no other children or pets in the bed, and no possibility of her falling or becoming trapped against a wall. Never, under any circumstances, on a sofa or an armchair.

Products that don't do what they suggest

A good deal of money is made from this fear. I'd rather you spent it on something else.

Consumer breathing and movement monitors. There's no evidence that they reduce the risk of sudden infant death, and safe-sleep bodies don't recommend them for that purpose. I bought one. It woke us both several times a week with false alarms, and it cost me more sleep than it ever saved.
Cot bumpers, sleep positioners, pods and nests, none of which are recommended for sleep, and several of which have been withdrawn.
Inclined sleepers and anything that props a baby up. These have been recalled after deaths. Reflux isn't a reason to incline a cot.
Weighted sleep sacks and weighted blankets for infants, which safe-sleep authorities advise against.
Any mattress, sheet or gadget marketed with a claim about preventing sudden infant death. No product has been shown to do this.

What works is free, which I found difficult to accept while frightened, because being frightened makes you want to buy something, and I bought a monitor I never trusted and a mattress I didn't need.

What to do about the fear

The fear itself deserves a section, because for many of us it's the loudest thing in the first four months and almost nobody writes about it.

I checked on Shan constantly, in the way you do when the thing you are frightened of has no warning sign to watch for. I stood over the cot with my hand near her back at two, three and four in the morning. On the nights she slept longer than usual I lay awake, pleased and terrified in equal measure, which I don't think made me unusual so much as it made me a first-time mother in month three.

Two things helped, and neither was reassurance from anybody. The first was doing the list properly and then stopping: going through the room once before bed, checking the cot is clear and flat and she's on her back, and then treating it as settled for the night. The second was moving her cot alongside the bed so I could see her without getting up, which the guidance recommends anyway for the first six months.

If the fear has become something you can't put down, if you're not sleeping when she sleeps because you're watching her, or if intrusive thoughts about her dying arrive during the day, please tell a doctor or your health visitor. It's common and treatable in the first year, it's asked about routinely, and saying it out loud doesn't put your child at any risk whatsoever. It took me far too long to work that out.

What I read

This guide is general information, written to help you understand a topic and ask better questions. It is not medical advice and does not replace your own doctor, midwife or paediatrician. Anything that worries you about your baby belongs with them.

If this was your night too

← More on health & safety All 177 guides