The ABCs, and the space
Remember this simple but crucial acronym: ABC. It’s the foundation of the American Academy of Pediatrics (AAP) safe sleep recommendations for a baby’s first year, and it’s easy to remember even when you’re sleep-deprived.
- A - Alone: No stuffed animals, blankets, pillows, or other items in the sleep space
- B - Back: Always place baby on their back for every sleep
- C - Crib: In a safety-approved crib, bassinet, or play yard with a firm mattress
Comfort matters, and it isn't one of the ABCs. That distinction is worth holding: you can have both, and the safe version comes first.
Then the space itself, where each element matters.
- Firm mattress - No softness or sinking
- Fitted sheet only - No loose bedding
- Empty space - No toys, pillows, or positioners
- Proper assembly - No drop-side cribs, all hardware secure
On their back, and not too warm
Overheating is a serious risk factor for SIDS. Consider the room's ambient temperature when you dress them, and dress them in one more layer than you're comfortable wearing. Avoid covering their face and head. And check for the signs: sweating, a chest that feels hot.
A room around 68 to 72°F, or 20 to 22°C, is often given as a comfortable range. It is guidance rather than a rule, because the AAP does not specify a number. What matters more is watching for the signs of overheating.
Back sleeping is the other half of it, and it works for four reasons. It prevents rebreathing exhaled carbon dioxide. It allows better temperature regulation. It keeps the protective airway reflexes working. And it dramatically lowers SIDS risk.
Always place your baby on their back to sleep, even if they can roll over. Once they can roll both ways independently, they can choose their sleep position, but you still start them on their back.
When to stop swaddling
Swaddling can be comforting for newborns, but it must be done safely and stopped at the right time.
Safe swaddling practices:
- Hip-healthy - loose enough around hips for leg movement
- Chest-comfortable - not too tight around chest or lungs
- No overheating - use lightweight, breathable fabrics
- Know when to stop - at the first sign of rolling, which can be as early as 2 months.
Some babies start rolling as early as 2 months of age, but every baby is different. The moment your baby shows any signs of rolling, switch to a sleep sack or wearable blanket. Swaddling restricts movement that babies need for safe rolling. If your baby can break out of a swaddle, it’s time to switch to a sleep sack or wearable blanket. Breaking free can leave a loose blanket in the sleep space, which poses a safety risk.
Where they sleep
Room-sharing reduces SIDS risk by up to 50%, but bed-sharing can increase risks significantly.
- Room-sharing: your baby sleeps in your room, in their own sleep space, for at least the first 6 months, and ideally the first year.
- Bed-sharing risks: Adult bedding, pillows, and rolling hazards
- Emergency planning: if you fall asleep with your baby by accident, 'If a safe-sleep rule gets broken' below says what to do.
Bed-sharing, or co-sleeping, where parents and infants sleep in the same bed, is discouraged in the official AAP guidelines and in many others. It is still a very common way of sleeping across the globe. If you do choose it, the steps below reduce the risk rather than remove it, so you can decide with the facts in front of you.
- Keep pillows and adult bedding away from the baby.
- Remove headboards with vertical bars or decorative designs.
- Don’t bring other children or pets into the bed with you.
- Make sure there are no gaps where baby could get trapped, such as between the mattress and the wall.
- Use a firm adult mattress, never a sofa, armchair, waterbed or recliner.
- Don’t leave the baby alone in an adult bed.
- Bed-sharing is not safe if anyone in the bed smokes, has been drinking or using anything sedating, or is very unwell or exhausted, or if your baby was born early or small.
Having your baby close by in their own sleep space makes night feeds easier and significantly reduces SIDS risk. I'd call that the arrangement with the fewest trade-offs in the whole topic.
The other things that help
Beyond the sleep environment, several other things affect your baby's safety. Offering a pacifier at sleep time, once breastfeeding is established. Breastfeeding itself, which is associated with reduced SIDS risk. A smoke-free environment, during pregnancy and after birth. Up-to-date immunizations, which protect against SIDS. And supervised tummy time, which strengthens neck and shoulder muscles.
Every layer of protection counts on its own. I'd rather you followed most of these than gave up because you cannot manage all of them.
The rules that don’t bend
Here is a safe sleep plan you can use tonight.
Your Safe Sleep Promise:
- ABC compliance: Alone, Back, Crib for every sleep
- Temperature check: One more layer than you're comfortable wearing, and check for signs of overheating (sweating, chest feeling hot)
- Environment audit: Firm mattress, fitted sheet only, empty crib
- Risk reduction: Pacifier offered, smoke-free home, up-to-date care
- Emergency prep: know what to do if a safety rule gets broken.
Perfection isn't the goal here, consistency is. If a safety rule slips, the next screen is what to do, and I'd say the short version is that one slip does not undo anything.
If a safe-sleep rule gets broken
It happens. You fall asleep holding them, the sleep sack comes undone, a blanket ends up in the crib. What matters now is what you do next.
If your baby is sleeping and breathing normally, move them to their own flat, firm sleep space, on their back, and carry on.
If they were under a blanket, wedged, or sleeping on something soft, pick them up and check on them. If they are hard to rouse, floppy, or their breathing looks wrong, call emergency services.
If this has happened more than once, it is worth telling your doctor because exhaustion that deep usually has a cause worth looking at.
The best preparation for this is an infant first-aid course. Keep your out-of-hours number somewhere you can find it fast.
- Rachel Y. Moon et al., “Evidence Base for 2022 Updated Recommendations for a Safe Infant Sleeping Environment to Reduce the Risk of Sleep-Related Infant Deaths,” Pediatrics 150, no. 1 (2022): e2022057991, https://doi.org/10.1542/peds.2022-057991.
- Moon et al., “Evidence Base for 2022 Updated Recommendations for a Safe Infant Sleeping Environment to Reduce the Risk of Sleep-Related Infant Deaths.”
- Jeffrey D. Colvin et al., “Sleep Environment Risks for Younger and Older Infants,” Pediatrics 134, no. 2 (2014): e406–12, https://doi.org/10.1542/peds.2014-0401.
- Fern R. Hauck et al., “Breastfeeding and Reduced Risk of Sudden Infant Death Syndrome: A Meta-Analysis,” Pediatrics 128, no. 1 (2011): 103–10, https://doi.org/10.1542/peds.2010-3000.
- Carrie K. Shapiro-Mendoza et al., “Recent National Trends in Sudden, Unexpected Infant Deaths: More Evidence Supporting a Change in Classification or Reporting,” American Journal of Epidemiology 163, no. 8 (2006): 762–69, https://doi.org/10.1093/aje/kwj117.
- Véronique Bach and Jean-Pierre Libert, “Hyperthermia and Heat Stress as Risk Factors for Sudden Infant Death Syndrome: A Narrative Review,” Frontiers in Pediatrics 10 (April 2022): 816136, https://doi.org/10.3389/fped.2022.816136.
- Cleveland Clinic, Sleep in Your Baby’s First Year, 2023, https://my.clevelandclinic.org/health/articles/14300-sleep-in-your-babys-first-year.
- Bregje E. Van Sleuwen et al., “Swaddling: A Systematic Review,” Pediatrics 120, no. 4 (2007): e1097–106, https://doi.org/10.1542/peds.2006-2083.
- Anna S. Pease et al., “Swaddling and the Risk of Sudden Infant Death Syndrome: A Meta-Analysis,” Pediatrics 137, no. 6 (2016): e20153275, https://doi.org/10.1542/peds.2015-3275.
- Peter S. Blair et al., “Bed-Sharing and SIDS: An Evidence-Based Approach,” Archives of Disease in Childhood 108, no. 4 (2023): e6–e6, https://doi.org/10.1136/archdischild-2021-323469.
- Lauren R. Rechtman et al., “Sofas and Infant Mortality,” Pediatrics 134, no. 5 (2014): e1293–300, https://doi.org/10.1542/peds.2014-1543.
- Hauck et al., “Breastfeeding and Reduced Risk of Sudden Infant Death Syndrome.”
- M. M. T. Vennemann et al., “Do Immunisations Reduce the Risk for SIDS? A Meta-Analysis,” Vaccine 25, no. 26 (2007): 4875–79, https://doi.org/10.1016/j.vaccine.2007.02.077.
Even items that seem harmless, like small blankets or breathable bumpers, aren't recommended for safe sleep. An empty crib is a safe crib.