Every year about 3,400 babies in the United States die suddenly and unexpectedly during sleep. Many of these deaths are linked to an unsafe sleep environment. Following a short set of evidence-based rules dramatically lowers the risk. The American Academy of Pediatrics updated its safe sleep recommendations in 2022, and the core message remains simple: place your baby Alone, on their Back, in a Crib (AAP 2022, NICHD Safe to Sleep).
Building a bedtime routine? The bedtime routine planner creates a timed wind-down plan for babies and toddlers. For age-matched sleep targets, use the baby 24-hour sleep calculator.
The ABCs Of Safe Sleep
The easiest way to remember safe sleep is the ABC rule (HealthyChildren.org):
- A – Alone. The baby sleeps alone in their own sleep space. No pillows, blankets, bumpers, stuffed animals or other people in the crib. A wearable blanket or sleep sack replaces loose bedding.
- B – Back. Always place the baby on their back for every sleep, including naps. Back sleeping is the single most important step to reduce SIDS risk.
- C – Crib. Use a crib, bassinet or play yard with a firm, flat mattress and a fitted sheet. No inclined sleepers, car seats, swings or sofas for unsupervised sleep.
What Is SIDS?
Sudden infant death syndrome is the unexplained death of a baby under 1 year old, usually during sleep. It is sometimes called crib death. The exact cause is not known, but researchers believe it involves a combination of a vulnerable baby, a critical period of development, and an unsafe sleep environment (NICHD).
SIDS risk is highest between 1 and 4 months of age and declines after 6 months. About 90 percent of SIDS deaths occur before 6 months (Stanford Children’s Health). Boys are slightly more likely to be affected than girls, and premature or low-birth-weight babies face a higher risk (NHS).
AAP Safe Sleep Guidelines (2022 Update)
The AAP published updated recommendations in June 2022. The key points are (AAP 2022, HealthyChildren.org):
- Place babies on their back for every sleep until their first birthday.
- Use a firm, flat, non-inclined surface. The mattress should fit snugly in the crib with no gaps.
- Keep the sleep area clear of all soft objects, loose bedding and bumpers.
- Room-share (baby sleeps in the parents’ room in their own crib or bassinet) for at least the first 6 months.
- Do not bed-share. Bed-sharing on a soft surface such as a couch, armchair or waterbed is particularly dangerous.
- Offer a pacifier at nap time and bedtime after breastfeeding is established.
- Avoid overheating. Dress the baby in no more than one single extra layer than an adult would wear.
- Do not use home monitors or commercial devices marketed to reduce SIDS risk. None have been proven effective.
Room-Sharing vs. Bed-Sharing
Room-sharing means the baby sleeps in their own crib or bassinet within arm’s reach of the parents’ bed. This arrangement is linked to a lower SIDS risk, likely because parents can hear and respond to the baby more quickly (HealthyChildren.org).
Bed-sharing means the baby sleeps in the same bed as an adult. The AAP recommends against it because adult mattresses, pillows and blankets create suffocation hazards. The risk is highest when a parent smokes, has consumed alcohol, or is extremely tired, and when the baby is younger than 4 months or was born premature (March of Dimes, NHS).
If a parent falls asleep while feeding, the safest place is a bed with no soft bedding, rather than a sofa or armchair, which carry the highest suffocation risk. Move the baby back to their crib as soon as you wake (AAP Safe Sleep).
Swaddling: Rules And When To Stop
Swaddling can help a newborn feel secure and reduce the startle reflex. To swaddle safely (HealthyChildren.org, March of Dimes):
- Always place a swaddled baby on their back.
- Keep the swaddle snug around the chest and arms but loose at the hips so the legs can bend and move freely.
- Stop swaddling as soon as the baby shows any sign of rolling. This can happen as early as 2 months.
- A swaddled baby who rolls face-down cannot push up to clear the airway.
Once swaddling stops, switch to a sleep sack with arms free. These keep the baby warm without the suffocation risk of a loose blanket. For a broader guide to setting up the sleep environment, see our ideal sleep environment guide.
Pacifiers And SIDS Risk
Several studies have found that using a pacifier during sleep is associated with a lower SIDS risk. The AAP recommends offering one at nap time and bedtime (HealthyChildren.org). If the baby is breastfed, wait until breastfeeding is well established, usually around 3 to 4 weeks, before introducing a pacifier. If the baby does not want it, do not force it. If it falls out during sleep, you do not need to put it back (KidsHealth).
Risk Factors You Can Control
| Risk factor | What to do |
|---|---|
| Stomach or side sleeping | Always place on back |
| Soft bedding, pillows or bumpers | Remove everything except a fitted sheet |
| Overheating | Keep room at 68 to 72 F; one layer more than an adult |
| Smoking (during pregnancy or after) | Do not smoke and keep the home smoke-free |
| Bed-sharing | Room-share without sharing the bed |
| Premature or low birth weight | Follow safe sleep rules even more carefully |
| No prenatal care | Get regular prenatal check-ups |
Sources: Stanford Children’s Health, NHS, NICHD.
When Does SIDS Risk Go Down?
The peak risk window is 1 to 4 months. After 6 months the risk drops significantly, and after 12 months SIDS is rare (Stanford Children’s Health). However, safe sleep practices should continue through the first birthday. The baby sleep calculator adjusts its bedtime recommendation as the baby grows, and the baby sleep schedule by age guide covers the full first year.
Common Safe-Sleep Mistakes
- Letting the baby sleep in a car seat outside the car. Car seats are designed for travel, not sleep. The incline can cause the baby’s head to fall forward and restrict breathing (AAP).
- Adding a blanket “just this once.” Even one loose blanket raises the risk. Use a sleep sack instead (March of Dimes).
- Using crib bumpers. Both padded and mesh bumpers pose risks and are not recommended (AAP 2022).
- Relying on monitors. No home monitoring device has been proven to prevent SIDS. They can create a false sense of security (AAP 2022).
- Falling asleep with the baby on a sofa. Couches and armchairs are among the most dangerous places for a baby to sleep. If you feel yourself drifting off, move the baby to the crib first (AAP).
Creating A Safe Sleep Space
Setting up the nursery correctly from the start prevents most sleep-related risks. Whether you are preparing for a first baby or refreshing the setup for a second child, go through this checklist before the baby arrives (HealthyChildren.org, AAP):
- Choose a certified crib, bassinet or play yard. Look for a JPMA certification seal. Avoid used cribs with missing hardware, wide slats, or a drop-side mechanism.
- Pick the right mattress. It should be firm and flat. Press the center and edges. If it conforms to your hand, it is too soft. The mattress must fit the crib tightly with no gaps wider than two fingers between the mattress edge and the crib side.
- Use only a fitted sheet. No flat sheets, blankets or quilts. The fitted sheet should be snug and designed for that specific mattress size.
- Position the crib away from hazards. Keep it away from windows, blinds with cords, wall-mounted shelves and space heaters. Anything within the baby’s reach could become a strangulation or suffocation hazard.
- Set the room temperature. Aim for 68 to 72 degrees Fahrenheit. A simple room thermometer takes the guesswork out of getting this right. Dress the baby in a sleep sack rather than adding loose blankets on top (NHS).
- Keep the crib completely bare. No wedges, positioners, stuffed animals, bumper pads or decorative pillows of any kind until the child is at least 12 months old.
For a broader look at how lighting, noise and temperature affect infant sleep quality, see the newborn sleep guide. And for sleep needs across every stage of childhood, the children’s sleep guide covers newborn through teen.
FAQs
Can My Baby Sleep On Their Stomach If They Roll There?
Once a baby can roll both ways on their own, you do not need to reposition them. Always start on the back, but if they roll during sleep it is generally considered safe (HealthyChildren.org).
Is It Safe To Use A Second-Hand Crib?
Only if it meets current safety standards. Check that no parts are missing, the slats are no more than 2 and 3/8 inches apart, the mattress fits snugly with no gaps, and the crib has not been recalled. Drop-side cribs are banned and should not be used (March of Dimes).
Do I Need A Special Mattress To Prevent SIDS?
No. You need a firm, flat mattress that fits the crib tightly. Specialty mattresses marketed for SIDS prevention have no proven benefit (AAP 2022).
How Warm Should The Baby’s Room Be?
Keep the room between 68 and 72 degrees Fahrenheit (20 to 22 Celsius). Dress the baby in one layer more than you would wear. If the baby’s chest feels hot or sweaty, remove a layer (NHS).
Should I Use A Fan In The Baby’s Room?
A ceiling or room fan helps circulate air and may lower SIDS risk slightly. It also helps prevent overheating. Keep it out of direct reach of the crib (KidsHealth).
What If My Baby Hates Sleeping On Their Back?
Some babies fuss when placed on their back at first. A snug swaddle (before rolling starts) or a pacifier can help them settle. Tummy time while awake builds the neck strength that makes back sleeping more comfortable over time (HealthyChildren.org).
Is Bed-Sharing Ever Safe?
The AAP recommends against bed-sharing in all circumstances. The risk is highest with a baby under 4 months, a premature baby, or when a parent has consumed alcohol or sedating medication. If a parent falls asleep unintentionally, a firm adult bed with no pillows or blankets near the baby is less dangerous than a sofa or recliner (AAP).