A newborn should always sleep on their back, on a firm and flat surface, with no loose bedding, pillows, or soft toys in the sleep area. This single setup is the most effective way to reduce the risk of sleep-related infant death, and it applies to every sleep, whether it’s nighttime or a daytime nap. Beyond positioning, there are several practical details about environment, temperature, feeding, and sleep patterns that will help you keep your baby safe and get through those first exhausting months.
Why Back Sleeping Is Safest
When a baby sleeps on their back, the windpipe (the tube leading to the lungs) sits above the esophagus (the tube leading to the stomach). This means that if your baby spits up while sleeping, the fluid has to work against gravity to reach the airway. It’s a natural safeguard against choking.
Flip that picture upside down and you see the problem with stomach sleeping. When a baby is face down, the opening to the stomach sits above the airway, and gravity pulls any spit-up fluid directly toward the lungs. This is one of the key reasons health authorities have recommended back sleeping since the 1990s. Many parents worry that back sleeping increases choking risk, but the anatomy shows the opposite is true.
Place your baby on their back for every sleep until their first birthday. Once babies can roll both ways on their own, you don’t need to reposition them if they flip during the night, but you should still always place them on their back to start.
Setting Up a Safe Sleep Surface
Your baby’s sleep area should be firm, flat, and free of extras. That means a safety-approved crib, bassinet, or play yard with a snug fitted sheet and nothing else. No blankets, no pillows, no bumper pads, no stuffed animals. These items can press against a baby’s face and obstruct breathing, and infants lack the strength and coordination to push them away.
The surface should never be inclined or angled. Products marketed as “sleepers” with an incline have been linked to infant deaths and multiple recalls. A flat mattress is the standard. If you’re using a hand-me-down crib, make sure the mattress fits tightly with no gaps between the mattress edge and the crib frame. A good test: if you can fit more than two fingers between the mattress and the side of the crib, the mattress is too small.
Room Sharing Without Bed Sharing
Placing your baby’s crib or bassinet in your bedroom, ideally for at least the first six months, reduces the risk of SIDS by as much as 50%. Room sharing makes nighttime feeding easier and lets you monitor your baby’s breathing and positioning without getting out of bed.
Bed sharing is a different matter entirely. Adult mattresses, pillows, and blankets all pose suffocation risks, and a sleeping adult can inadvertently roll onto an infant. The safest arrangement is your baby in their own sleep space, within arm’s reach of your bed. If you find yourself falling asleep while feeding your baby in bed, remove all pillows and blankets beforehand as a precaution, and move the baby back to their own sleep surface as soon as you wake.
Room Temperature and What to Dress Them In
Keep the room between 68 and 78°F (20 to 26°C). A small fan on a low setting can help circulate air and has been associated with lower SIDS risk in some studies. The goal is a comfortable environment where your baby doesn’t overheat, since overheating is an independent risk factor for sleep-related deaths.
Since blankets are off the table, dress your baby in a one-piece sleeper or use a wearable blanket (sleep sack) for warmth. A good rule of thumb: dress your baby in one layer more than you’d wear comfortably in the same room. If their chest feels warm and dry to the touch, they’re fine. Sweating, flushed cheeks, or damp hair at the back of the neck are signs they’re too warm.
Swaddling Safely
Swaddling can soothe newborns by mimicking the snug feeling of the womb, and it helps reduce the startle reflex that wakes them. If you swaddle, keep the wrap snug around the arms but loose around the hips to allow healthy hip development. The swaddle should never cover the baby’s face or come loose enough to become a suffocation risk.
The critical rule: stop swaddling as soon as your baby shows any signs of trying to roll over. Some babies start working on rolling as early as two months. A swaddled baby who rolls onto their stomach can’t use their arms to push up or reposition, which makes the situation dangerous. Once you retire the swaddle, a sleep sack with open armholes is a safe alternative for warmth.
What Normal Newborn Sleep Looks Like
Newborns sleep roughly 16 to 17 hours per day, but they rarely sleep more than one or two hours at a stretch. This is biologically normal, even though it feels relentless. Their stomachs are tiny and digest breast milk or formula quickly, so they need to eat frequently throughout the day and night.
Babies don’t develop regular, predictable sleep cycles until around six months of age. Before that, their sleep is scattered across the 24-hour day with no real distinction between daytime and nighttime. Around four to six weeks, your baby will start responding more to light and dark changes as their internal body clock begins to develop. You can gently encourage this process by keeping daytime feeds bright and interactive and nighttime feeds dim and quiet, but don’t expect a dramatic shift right away. The early weeks are about survival, not schedules.
Feeding and Sleep in the First Weeks
In the first weeks, babies need to eat every two to four hours, and you may need to wake your baby to feed. This is especially important for newborns who haven’t yet regained their birth weight. Once your pediatrician confirms that weight gain is on track, you can typically let your baby sleep until they wake on their own for feeds.
Nighttime feedings will gradually space out as your baby’s stomach grows and they can take in more at each feeding. By two to three months, many babies can go one longer stretch of four to five hours, often in the first half of the night. This varies widely, and feeding on demand remains the safest approach for the first several months. If your baby is sleeping for unusually long stretches in the first few weeks and seems difficult to wake, that’s worth mentioning to your pediatrician, as very sleepy newborns sometimes aren’t getting enough nutrition.
Pacifiers, Smoke, and Other Risk Factors
Offering a pacifier at sleep time is associated with a lower risk of SIDS. If you’re breastfeeding, it’s generally fine to introduce a pacifier once nursing is well established, usually around three to four weeks. If the pacifier falls out after your baby is asleep, you don’t need to put it back in.
Exposure to cigarette smoke, both during pregnancy and after birth, significantly increases SIDS risk. This includes secondhand smoke in the home or car. Keeping your baby’s environment smoke-free is one of the most impactful things you can do beyond safe sleep positioning. Alcohol and sedating medications also impair a caregiver’s ability to respond to a baby, making bed sharing particularly dangerous under those circumstances.