Crib safety basics

The AAP safe sleep rules

Back to sleep, every sleep

Always place baby on their back to sleep, for naps and at night. The supine position is the single most important factor. Once baby can roll both ways consistently, you no longer have to reposition them — but you still start them on their back. Stomach sleeping is associated with a roughly 13-fold increase in SIDS risk.

Firm flat surface

The mattress in the crib should be firm to the point that it does not indent when you press a hand into it. Soft mattresses, foam mattresses with sinking surfaces, and any product that conforms to the baby's shape is unsafe. Babies have suffocated on softer surfaces.

The mattress must fit the crib snugly. If you can fit more than two fingers between the mattress and the crib side, the mattress is too small. Use the mattress made for that specific crib (or a properly sized aftermarket one).

Nothing in the crib

This is the rule parents struggle with the most. The list of things that should not be in the crib:

• Blankets, quilts, comforters.
• Pillows.
• Bumpers (banned federally as of 2022, but older ones still circulate).
• Sleep positioners or wedges.
• Stuffed animals.
• Crib tents or netting.
• Loose toys.
• Pacifier clips or pacifier-with-attached-plush.
• Necklaces, bracelets, hair clips.
• Loose mesh liners.

What can be in the crib: the fitted sheet on the firm mattress, and the baby. A pacifier without an attached object is fine.

Same room, separate surface

Babies should sleep in the same room as a parent for the first 6 months (the AAP also notes through 12 months for higher-risk babies). Same room does not mean same bed. Room-sharing reduces SIDS risk by about 50 percent. The bassinet or crib is on a stand near the parents' bed.

Bed-sharing is associated with higher SIDS risk, especially under 4 months. If parents may fall asleep with baby, the AAP says it is safer to do so in bed than on a couch or armchair (which carry the highest risk) and to remove pillows and blankets from the area around the baby.

Breastfeeding when possible

Any breastfeeding reduces SIDS risk. Exclusive breastfeeding for 6 months reduces it more. The risk reduction is real but it does not replace the other rules; back-sleeping in a bare crib is still required for formula-fed babies and breastfed babies alike.

Pacifier at sleep onset

Offering a pacifier when laying baby down for sleep is associated with lower SIDS risk. Once asleep, if it falls out, no need to replace. For breastfed babies, delay pacifier introduction until breastfeeding is established (typically around 3 to 4 weeks).

No smoke exposure

No smoking during pregnancy. No one smokes around the baby. Smoke exposure dramatically raises SIDS risk.

Vaccines on schedule

On-time immunization correlates with about 50 percent lower SIDS risk in observational studies. Stay current.

Avoid overheating

Bedroom 68 to 72 degrees Fahrenheit. One layer more than an adult would wear. Skip the hat indoors. A sleep sack instead of loose blankets. Babies overheated regulate temperature poorly.

Tummy time when awake

Supervised tummy time strengthens neck muscles and prevents flat spots. Start from day 1 with short sessions. The tummy time rule is awake and supervised only — never sleeping prone.

What the crib itself should look like

• Slats no more than 2 3/8 inches apart (the width of a soda can). Wider slats are an entrapment risk.
• No cutout designs in the head- or footboards. Entrapment hazard.
• No drop sides (banned since 2011). If your hand-me-down crib has a drop side, do not use it.
• Mattress support that does not pop out under pressure.
• No cracked, peeling, or chipped paint. Lead concern in pre-1978 cribs.
• Hardware tight, no missing screws.
• Mattress at the lowest setting once baby can sit (typically 6 to 8 months).
• Crib located away from windows, blind cords, and outlets.

Cribs to skip

• Cribs made before 2011 (last drop-side standard pre-ban year).
• Cribs with any cracked or broken parts.
• Cribs with peeling paint.
• Cribs missing the model number or instructions (you can't verify recall status).
• Convertible cribs with toddler-bed conversion kits that don't lock securely.
• Cribs that have been in storage in damp basements or attics. Mold and structural concerns.
• Stand-alone "co-sleeping" surfaces sold internationally that have not passed US safety standards.

Inclined sleepers, weighted swaddles, and other recalled categories

Several categories of "sleep" products have been linked to infant deaths and either banned or recalled:

• Inclined sleepers. The Fisher-Price Rock 'n Play recall in 2019 set a clear standard: inclined sleep above 10 degrees is unsafe. Do not use anything that elevates baby's head while sleeping.
• Weighted swaddles and blankets. The AAP recommends against weighted sleep products. The weighted swaddle category was recalled in 2022.
• In-bed sleepers and pods. Several "snuggling" products marketed for in-bed sleep have been linked to deaths. The AAP does not endorse them.
• Crib tents. Linked to entrapment and asphyxiation. Avoided.
• Sleep positioners and wedges. Long banned for in-crib use.

What to do as baby grows

• 4 to 6 months: baby starts rolling. Lower the mattress to mid-height. Stop using a swaddle. Transition to a sleep sack with arms in.
• 6 to 9 months: baby starts sitting and pulling up. Lower the mattress to the lowest setting.
• 12 months: blankets and pillows are still officially not recommended in the crib by the AAP. Some pediatricians and parents do introduce a thin blanket after 12 months.
• 18 to 36 months: transition out of the crib when baby is climbing out (a fall risk that outweighs the crib's containment benefit) or after age 3 if not yet transitioning.