Babies should always sleep on their backs, on a firm and flat surface, in their own sleep space with nothing else in it. That three-part rule is the foundation of every safe sleep recommendation from major pediatric organizations, and following it has cut sudden infant death syndrome (SIDS) rates by roughly 50% since public health campaigns began in the early 1990s.
Beyond that core rule, the details matter: room temperature, when to stop swaddling, where to place the crib, and how to handle nighttime feedings all play a role in keeping your baby safe and helping everyone get more sleep.
The ABCs: Alone, on Their Back, in a Crib
Every sleep session, whether nighttime or a nap, should follow the same setup. Place your baby on their back in a crib, bassinet, or portable play yard with a firm, flat mattress and a fitted sheet. Nothing else goes in there: no loose blankets, no pillows, no stuffed animals, no bumper pads. Padded crib bumpers are actually banned under the Federal Safe Sleep for Babies Act because they can obstruct an infant’s breathing and pose a suffocation risk.
The back-sleeping position is non-negotiable for young infants. Before public health campaigns promoted it, stomach sleeping was common, and SIDS rates were significantly higher. In Norway, the SIDS rate halved within a single year of launching a back-to-sleep campaign. Once your baby can roll both ways on their own, you don’t need to reposition them if they flip during sleep, but you should always place them down on their back to start.
Avoid letting your baby sleep on a couch, armchair, or in a device like a swing or car seat (unless they’re riding in the car). If your baby falls asleep in an inclined or upright position, move them to a flat sleep surface as soon as you can.
Room Sharing vs. Bed Sharing
The American Academy of Pediatrics recommends keeping your baby’s crib or bassinet in your bedroom for at least the first six months. Room sharing (not bed sharing) reduces the risk of SIDS by as much as 50% compared to having the baby sleep in a separate room. Having the baby within arm’s reach makes nighttime feedings easier and lets you monitor their breathing without fully waking up.
Bed sharing is a different story. Sharing an adult mattress with an infant increases the risk of suffocation, overheating, and overlay. Adult beds aren’t designed with infant safety in mind: soft mattresses, pillows, and blankets all create hazards. The safest arrangement is a separate sleep surface right next to your bed.
Room Temperature and What to Wear
Overheating is a known risk factor for SIDS. The recommended room temperature for a sleeping baby is 16 to 20°C (roughly 61 to 68°F). A good rule of thumb: dress your baby in one layer more than you’d be comfortable wearing in the same room. If the room feels comfortable to you in a t-shirt, your baby is fine in a onesie and a light sleep sack.
Check your baby’s chest or the back of their neck to gauge temperature. Hands and feet tend to run cool in infants and aren’t a reliable indicator. If your baby’s chest feels hot or sweaty, remove a layer.
Swaddling: When to Start and Stop
Swaddling can help newborns sleep more soundly by reducing their startle reflex. A snug wrap around the torso with hips loose enough to bend naturally is the standard technique. But swaddling has a firm expiration date: you need to stop as soon as your baby shows signs of rolling over. A swaddled baby who rolls onto their stomach can’t use their arms to push up or reposition, which creates a suffocation risk.
Most babies start attempting to roll between two and four months. Once you retire the swaddle, a wearable sleep sack is a safe alternative that keeps your baby warm without restricting arm movement.
Pacifiers and SIDS Risk
Offering a pacifier at sleep time is associated with a lower risk of SIDS. A large pooled analysis of case-control studies found that pacifier use during sleep cut the risk roughly in half. Researchers believe several mechanisms may explain this: the pacifier may help keep the airway open, promote lighter sleep that makes it easier for the baby to rouse, and discourage stomach sleeping.
If you’re breastfeeding, it’s generally fine to introduce a pacifier once nursing is well established, typically around three to four weeks. If the pacifier falls out after your baby is asleep, you don’t need to put it back in.
Understanding Infant Sleep Patterns
Newborn sleep looks nothing like adult sleep, and understanding that can save you a lot of frustration. A newborn’s sleep cycle lasts only about 45 to 60 minutes, compared to roughly 90 minutes for adults. Babies also spend a much larger proportion of their sleep in REM (the lighter, more active stage), which is why they twitch, grunt, make faces, and wake easily. This isn’t a problem to fix. It’s normal brain development happening in real time.
As your baby grows, the balance gradually shifts toward deeper, quieter sleep stages, and sleep cycles get longer. By around three to four months, many babies start consolidating sleep into longer stretches at night, though there’s a wide range of normal.
Dream Feeds for Longer Stretches
A dream feed is a feeding you give while your baby is still asleep, typically between 10 p.m. and midnight, right before you go to bed yourself. The idea is simple: topping off your baby’s stomach can extend their longest sleep stretch by three to four hours, which means you both get more uninterrupted rest.
Dream feeds work best when started around two to three months of age. One added benefit is that because the baby is already asleep during the feed, they’re less likely to develop a habit of needing to suck in order to fall asleep. For breastfeeding parents, the late-night feed can also relieve the discomfort of full breasts before bed.
Tummy Time During the Day
Because babies spend so much time on their backs (as they should for sleep), supervised tummy time while awake is essential. It strengthens the neck, shoulder, and core muscles your baby needs to eventually roll, sit, and crawl. It also helps prevent flat spots from developing on the back of the head, a condition called positional plagiocephaly.
Start with two or three short sessions a day, just three to five minutes each. By around two months, aim for 15 to 30 minutes of total tummy time spread throughout the day. As your baby gets stronger and more comfortable, sessions can get longer. Many babies dislike tummy time at first. Getting down on the floor face-to-face with them or placing a small mirror in front of them can help.
Quick Reference: Safe Sleep Checklist
- Position: Always on their back for every sleep
- Surface: Firm, flat mattress with only a fitted sheet
- Space: Crib, bassinet, or play yard in your room for at least six months
- Temperature: Room at 16 to 20°C (61 to 68°F), no heavy clothing
- Nothing extra: No blankets, pillows, bumpers, or toys in the sleep area
- Pacifier: Offer one at sleep time once feeding is established
- Swaddle: Stop before your baby starts rolling