The safest form of co-sleeping is room-sharing, not bed-sharing: keep your baby's crib or bassinet in your bedroom, on its own firm, flat surface, close to your bed. The CDC notes room-sharing without bed-sharing can lower SIDS risk by up to 50%. Babies should always sleep on their backs, without soft bedding.
Co-sleeping is a broad term, and the difference between its two main forms matters more than the label itself. Room-sharing means your baby sleeps in the same room as you, but on a separate, dedicated sleep surface such as a crib, bassinet, or bedside co-sleeper. Bed-sharing means the baby sleeps on the same surface as an adult. The framework that runs through every section below is the Room-Sharing, Not Bed-Sharing approach recommended by the CDC, because it is the one setup where a specific, sourced safety benefit has been documented.
Every recommendation here follows CDC and AAP safe sleep guidance rather than personal opinion, and none of it replaces a conversation with your baby's pediatrician about your specific sleep setup.
The core safe co-sleeping guidelines from the CDC apply no matter which sleep surface your baby uses. Babies should be placed on their backs for every sleep, night and nap, until they are 1 year old. The sleep surface itself needs to be firm and flat — never a couch, armchair, adult mattress with soft padding, or any surface that indents around the baby's body.
Keep the sleep space itself bare: no pillows, loose blankets, crib bumpers, or soft toys near the baby. The single guideline with the clearest documented benefit is room-sharing without bed-sharing — keeping your baby's crib or bassinet in your bedroom, close to your bed, but on its own surface. The CDC states this practice can lower the risk of SIDS by up to 50% compared with a baby sleeping alone in a separate room.
Pairing a safe sleep surface with a calm bedtime routine can also help. If you are working on a consistent day-night rhythm alongside your co-sleeping setup, see baby sleep schedule for building that routine.
The Safe Sleep 7 is a checklist some breastfeeding advocates promote for families who choose to bed-share anyway, as a way to try to reduce risk rather than eliminate it. The seven conditions generally describe: a non-smoking household, a sober and unimpaired caregiver, a breastfeeding mother, the baby placed on its back, a lightly clothed baby (to avoid overheating), a firm flat surface with no gaps the baby could fall into, and no other children or pets sharing that same surface.
It's important to understand what the Safe Sleep 7 is and is not. It is a harm-reduction concept aimed at people who have already decided to bed-share. It is not the evidence-based standard that health authorities recommend as a first choice. The CDC and AAP continue to recommend room-sharing without bed-sharing for all infants, regardless of whether a parent is breastfeeding. Since the Safe to Sleep campaign launched in 1994, SIDS incidence in the United States has fallen by more than 50%, a decline widely attributed to consistent messaging around back sleeping, firm surfaces, and room-sharing rather than bed-sharing checklists.
If you are weighing bed-sharing against other options, talk it through with your pediatrician — see the guidance in the box below on when that conversation matters most.
At its simplest, co-sleeping means a baby sleeping in close proximity to a parent, but the term covers a wide spectrum. On one end is room-sharing: a newborn sleeps in a crib, bassinet, or bedside co-sleeper in the parent's bedroom, on its own firm surface. On the other end is bed-sharing: the newborn sleeps on the same mattress as one or more adults. When people ask "what is co-sleeping" in the context of newborn safety, health authorities are almost always distinguishing between these two, because the risk profile differs between them.
For a newborn specifically, the same core rules apply: back sleeping for every sleep, a firm and flat mattress, and a bare sleep space free of pillows, loose blankets, and bumpers. Keep the crib or bassinet within arm's reach of your bed so nighttime feeding and comforting don't require leaving the room. The CDC recommends keeping this room-sharing setup for at least the first six months, and ideally the first year, since that period carries the highest SIDS risk.
Rather than a photo, picture the setup this way: a bare crib or bassinet mattress with a tightly fitted sheet and nothing else in it — no pillow, no loose blanket, no bumper pads, no stuffed animals. The baby is dressed in a sleep sack or wearable blanket instead of loose bedding, placed flat on their back, with the crib or bassinet positioned right next to the parent's side of the bed. That bare, back-sleeping, firm-surface image is what the CDC and AAP illustrate in their own published safe sleep materials, and it's the mental picture worth keeping in mind when setting up any newborn sleep space.
For help soothing a newborn to sleep once the room-sharing space is set up, see baby sleep music and best noise machines for sleep.
A co-sleeping bassinet, often called a bedside bassinet or bedside sleeper, is a small bassinet that attaches to or sits flush against the side of the parent's bed, typically at roughly mattress height. It's built to support the room-sharing framework: the baby is close enough for easy nighttime access, but sleeps on its own dedicated surface rather than on the adult mattress. Many parents choose one specifically because it removes the need to lift a baby fully out of bed for a middle-of-the-night feeding while still keeping the baby off the shared adult surface.
Whatever sleep surface you choose — a standalone crib, a full-size bassinet, or a bedside co-sleeper — the mattress itself has to meet the same standard: firm and flat, with no indentation around the baby's body, and sized to fit the sleep space snugly with no gaps. This applies equally to every option; a soft or padded surface undermines the safety benefit of room-sharing regardless of which piece of furniture it's attached to. Pair the firm mattress with a fitted sheet only, and check that the product is sized and marketed for infant sleep rather than repurposed adult bedding.
Parents often ask whether co-sleeping shapes a baby's psychological development, independence, or attachment. This is an area where research findings are mixed and often based on small or anecdotal samples rather than the kind of large, sourced statistics used elsewhere in this guide, so it's worth being cautious about strong claims in either direction. Some parents who room-share report feeling more connected to their baby and find nighttime feeding and comforting easier when the crib or bassinet is close by. Others prioritize an earlier transition to independent sleep for reasons related to their own sleep quality or family routine.
What's better established than any specific psychological outcome is the physical safety case for room-sharing: the documented reduction in SIDS risk. If you're weighing co-sleeping decisions partly around your own sleep quality as a parent, it may help to read about core sleep and how sleep quality is measured, since parents balancing nighttime feeds often deal with fragmented sleep of their own. For soothing sounds that can support both baby and parent through the night, see colored noise for sleep.
Safe sleep questions are individual to each baby and family. Talk to your pediatrician if any of the following apply:
The AAP's safe sleep recommendations are a starting point, but your pediatrician can tailor guidance to your baby's specific needs.