Safe sleep guidance is one of the clearer public health successes. Campaigns promoting supine sleeping position from around the early 1990s coincided with substantial declines in sudden infant death rates across multiple countries.
The core points are few and worth stating precisely, because partial versions circulate.
The main recommendations
On the back, for every sleep. Not on the side, not on the front. Every sleep, including naps, and by every carer.
Side sleeping is not a safe alternative — it's unstable and infants can roll to prone.
Once a baby can roll both ways independently, they can be left in the position they adopt. They should still be placed on their back initially.
A clear sleep surface. A firm, flat mattress with a fitted sheet, and nothing else. No pillows, duvets, bumpers, positioners, soft toys or loose bedding.
Products marketed as sleep aids for cots — positioners, wedges, nests — are generally advised against, and several have been subject to safety warnings.
In the same room as a carer for the first six months, in their own separate sleep space. Room sharing without bed sharing is associated with reduced risk.
Smoke-free. Both in pregnancy and around the baby. Smoking exposure is among the strongest identified risk factors.
Avoid overheating. Room temperature comfortable rather than warm, and light bedding or a suitably weighted sleeping bag rather than heavy covers. Head uncovered.
Breastfeeding is associated with reduced risk in the epidemiological evidence.
Bed sharing, discussed honestly
An area where guidance has become more nuanced, because blanket advice was being ignored and leading to unsafe improvisation.
Bed sharing is associated with increased risk, and the risk varies enormously by circumstance.
The circumstances associated with substantially elevated risk are reasonably well characterised: where either parent smokes, has consumed alcohol or drugs including sedating medication, is extremely tired, on a sofa or armchair, or where the infant was premature or of low birth weight.
Sofa sharing in particular carries very high risk and is advised against unequivocally.
Given that many parents will bed share at some point, whether planned or through falling asleep while feeding, current guidance in several countries includes information on how to reduce risk if it happens: a firm flat surface, no pillows or duvets near the baby, baby on their back, no other children or pets in the bed, and none of the higher-risk circumstances present.
The reasoning is harm reduction. A parent who has been told never to bed share, and who falls asleep on a sofa while feeding at three in the morning, is in a considerably more dangerous situation than one who prepared the bed safely.
What isn't recommended
Home monitors marketed to prevent sudden infant death. No evidence that consumer monitoring devices reduce risk, and concerns about false reassurance and false alarms. Medical bodies have generally advised against relying on them.
Sitting devices for routine sleep. Car seats, bouncers and swings are not designed for sleep. Infants can adopt positions compromising their airway. If a baby falls asleep in a car seat, they should be moved to a flat surface when practical.
Inclined sleepers. Several products of this type have been recalled following safety concerns and deaths.
Dummies
Some evidence associates dummy use at sleep with reduced risk, and guidance in several countries mentions this.
The usual advice is to establish breastfeeding first if breastfeeding, and not to force it or replace it if it falls out during sleep.
Consistency across carers
A practical point that matters. Risk appears elevated when an infant accustomed to supine sleeping is placed prone by an unfamiliar carer.
Which means grandparents, childminders and anybody else caring for the baby need the same information, and guidance from a previous generation may differ substantially from current advice.
That conversation can be awkward and it's worth having explicitly.
Why the guidance is stated firmly
Worth acknowledging that safe sleep advice is sometimes experienced as anxiety-inducing, and that some parents find the tone difficult.
The reason for firmness is that the intervention is simple, free, and associated with large reductions in a devastating outcome. The cost of following it is low.
It's also worth saying that sudden infant death remains rare, that following the guidance substantially reduces risk without eliminating it, and that families who have experienced such a loss are not at fault.
General information only. Follow current safe sleep guidance from your national health authority, which is periodically updated, and discuss any concerns with your midwife, health visitor or doctor.
Travel and unfamiliar settings
Where safe sleep practice most commonly slips, and worth planning for.
Holidays, staying with relatives, and unfamiliar accommodation all present improvised sleeping arrangements — a bed pushed against a wall, a sofa, a travel cot with an unsuitable mattress.
Travel cots designed for the purpose, with their own firm mattress, are the straightforward answer and many places will provide one on request.
What is worth avoiding is the improvisation that happens at the end of a long journey when everybody is exhausted. Establishing where the baby will sleep before you arrive, rather than working it out at midnight, is the practical version of this advice.