Safe sleep practices have evolved as research has improved. This guide summarizes widely recommended crib safety basics.
Always follow guidance from your pediatrician and local health authorities.
The foundation: ABCs of safe sleep
Major health organizations recommend a consistent approach to infant sleep. The commonly taught framework is:
- Alone — baby sleeps alone in their own sleep space, not with adults, siblings, or pets on the same surface
- Back — place baby on their back for every sleep, including naps
- Crib — use a safety-approved crib, bassinet, or play yard with a firm, flat mattress
These principles apply whether baby sleeps in a nursery, your bedroom, or a caregiver’s home. Consistency across all sleep locations helps reduce risk.
The sleep surface
A safe crib or bassinet starts with the right surface. The mattress matters as much as the frame.
What a safe sleep surface includes
- A firm, flat mattress designed for that specific product — no softening pads, toppers, or inserts unless the manufacturer specifically approves them for overnight infant sleep
- A snug fitted sheet — you should not be able to fit more than two fingers between the mattress and the crib side
- No gaps where a baby’s head, body, or limbs could become trapped between mattress and frame
- Slats or sides with spacing that prevents head entrapment (current standards address this; avoid older cribs that may not meet them)
Mattress fit checklist
- Mattress is the size specified by the crib manufacturer
- No gaps larger than two fingers at any side
- Sheet fits tightly without bunching
- Mattress is firm — it should not conform to your hand when pressed
- No pillows, blankets, or padding under the sheet to “soften” the surface
Secondhand and older cribs
Avoid using secondhand cribs that do not meet current safety standards, or cribs with missing hardware, broken slats, or drop-side mechanisms. If you inherit a crib, inspect it thoroughly and confirm it has not been recalled. When in doubt, use a new crib or bassinet that meets current standards.
Browse nursery essentials for cribs, bassinets, and mattresses designed for infant sleep.
What not to put in the crib
The sleep area should contain only a fitted sheet and your baby in appropriate sleep clothing. Everything else increases risk.
Items to keep out of the crib
| Item | Why to avoid |
|---|---|
| Loose blankets, quilts, duvets | Suffocation and entanglement risk |
| Pillows, bolsters, positioners | Suffocation risk; not designed for infant sleep |
| Bumper pads (including mesh or “breathable” styles) | Entrapment and suffocation risk per many guidelines |
| Stuffed animals and toys during sleep | Suffocation risk |
| Weighted sleep products | Not recommended unless specifically directed by a clinician |
| Crib nests, loungers, or inclined sleepers marketed for overnight crib use | Not approved for unattended overnight sleep in a crib |
Dress baby in appropriate sleep clothing or a wearable blanket (sleep sack) instead of loose bedding. Sleep sacks come in different weights (TOG ratings) for different room temperatures — see our sleep-safe environment guide for temperature and clothing guidance.
Swaddling considerations
Some families swaddle newborns for sleep. If you swaddle:
- Stop swaddling when baby shows signs of rolling (usually around 2–4 months, but follow your baby’s development)
- Ensure the swaddle is snug at the arms but allows room at the hips
- Never place a swaddled baby on their stomach
- Follow your pediatrician’s guidance on swaddling for your baby
Crib placement in the room
Where you put the crib affects safety as much as what goes inside it.
Placement guidelines
- Keep the crib away from windows, blinds, and cords — blind cords are a strangulation hazard
- Do not place within reach of lamps, monitors, wall hangings, or anything that could fall into the crib
- Ensure no furniture a child could climb is adjacent to the crib as they grow (dressers, chairs, shelves)
- Keep the crib away from heaters, radiators, and direct sunlight that could overheat the sleep area
- Position monitor cords so they cannot be reached from the crib — mount or route cords far from the sleep surface
Room-sharing vs. bed-sharing
Major health organizations recommend room-sharing (baby in the same room as caregivers) for at least the first six months, without bed-sharing on soft adult mattresses. Room-sharing makes feeding easier and keeps baby within sight and reach.
Bed-sharing on soft surfaces (adult mattresses, couches, armchairs) is associated with increased risk. If you bring baby into your bed for feeding, plan how you will return them to their own sleep surface when feeding is done.
Our sleep-safe environment guide covers room setup, temperature, and routines in more detail.
Bassinet vs. crib
Many families use a bassinet in the bedroom for the first months, then transition to a full-size crib.
Bassinet considerations
| Factor | What to check |
|---|---|
| Weight limit | Most bassinets have a maximum weight (often 15–20 pounds) |
| Developmental milestones | Transition when baby rolls or pushes up — often before weight limit |
| Sleep surface | Firm, flat, with fitted sheet only — same rules as a crib |
| Placement | Same placement rules: away from cords, windows, and reachable hazards |
When baby rolls, pushes up on hands and knees, or reaches the weight limit — whichever comes first — move to a full-size crib with the mattress at the highest setting appropriate for a non-mobile infant.
Crib transition checklist
- Crib meets current safety standards
- Mattress at highest setting for a newborn who cannot sit or pull up
- Fitted sheet only in the sleep area
- Crib placed per room safety guidelines above
- Bassinet removed from room once transition is complete (avoid using both interchangeably without reason)
Adjusting the crib as baby grows
A crib is not a set-and-forget product. You will adjust it multiple times in the first two years.
When to lower the mattress
| Milestone | Action |
|---|---|
| Baby can push up on hands and knees | Lower mattress to middle setting |
| Baby can pull to stand | Lower mattress to lowest setting |
| Baby can climb out | Transition to a toddler bed or lower the mattress and remove climb aids |
As soon as baby can push up on hands and knees, lower the mattress to prevent falls. When they can pull to stand, use the lowest setting and remove any mobile or hanging items within reach.
Mobiles and hanging items
Remove mobiles and hanging toys when baby can push up or reach them — typically by 4–5 months. Strings and small parts become hazards once baby can grab them.
Monitor use
Video and audio monitors can offer reassurance but do not prevent unsafe sleep environments. A monitor does not replace a firm, empty crib or correct sleep position.
Monitor safety
- Place monitor cords far from the crib — cord strangulation is a real risk
- Follow manufacturer mounting guidance; do not attach monitors to crib rails
- Use monitors for awareness, not as a substitute for safe sleep setup
- Test range from your bedroom before relying on it at night
Browse health & safety for monitors that fit your home layout. Monitors are optional — many families sleep well without one.
Nap safety
Safe sleep rules apply to naps as well as nighttime sleep. The same crib or bassinet, same back position, same empty sleep surface.
- Avoid letting baby sleep in car seats, swings, or bouncers for extended periods — transfer to a firm, flat sleep surface when possible
- If baby falls asleep in a carrier, plan to move them to their crib or bassinet when practical
- Caregivers (grandparents, daycare) should follow the same safe sleep practices
Travel and alternate sleep spaces
When traveling or visiting, plan for a safe sleep surface.
- Pack-and-play or travel crib approved for overnight sleep
- Same rules: firm mattress, fitted sheet, no loose bedding
- Avoid using adult beds, couches, or soft surfaces for infant sleep
- Confirm hotel cribs meet safety standards or bring your own travel sleep space
Products to approach cautiously
Be skeptical of items that promise safer sleep through positioning wedges, inclined surfaces, or non-approved attachments. If a product is not marketed and tested for overnight sleep in a crib, do not use it for overnight sleep.
- Crib bumpers — not recommended by major health organizations despite “breathable” marketing
- Positioners and nests — not designed for unattended overnight sleep
- Weighted blankets or sleep sacks — not recommended for infants unless directed by a clinician
- Inclined sleepers in cribs — follow product-specific guidance; many are not for overnight crib use
When in doubt, ask your pediatrician before adding any product to the sleep area.
Related reading and gear
Setting up a safe nursery goes beyond the crib alone. For the full room plan, see:
- Nursery setup checklist — storage, lighting, and what to buy before baby arrives
- Creating a sleep-safe environment — temperature, clothing, routines, and sound
- Newborn essentials for the first month — focused gear list for the first 30 days
For gear that supports your nursery — from monitors to furniture — browse nursery essentials at Baby Common.