How to Choose a Safe Crib for Your Baby

Quick Answer

Choosing a safe crib is one of the highest-stakes gear decisions new parents make, because the sleep environment is where babies spend more time than anywhere else and where the risk of sleep-related infant death is most relevant. The good news is that the safety criteria are well established, regulatory standards have improved significantly over the past decade, and a safe crib does not need to be expensive. This guide covers the current safety standards to look for, the features that matter and those that do not, what to avoid, and how to set up the crib correctly once you have it.

Current Safety Standards

Crib safety standards vary by country, but the core requirements are consistent across the major regulatory frameworks:

• United States: Look for CPSC (Consumer Product Safety Commission) compliance and the ASTM F1169 standard for full-size cribs or ASTM F406 for non-full-size cribs. All cribs sold new in the US since 2011 must meet these standards, which banned drop-side cribs and tightened slat spacing and mattress fit requirements. A crib that meets current CPSC standards will state this on its packaging or listing
• United Kingdom: Look for BS EN 716 compliance for children's cots. The British Standards mark indicates the crib has been tested to the relevant UK/EU standard
• European Union: EN 716 applies across the EU for cots and cribs
• Australia and New Zealand: AS/NZS 2172 is the relevant standard for cots

When buying second-hand or using an inherited crib, the standard it was manufactured to is the critical question. Cribs manufactured before 2011 in the US may be drop-side models or may not meet current slat spacing and mattress fit standards. The safest approach with an older crib is to verify the standard it meets and replace it if it predates current requirements. Sentimental value does not outweigh sleep safety.

Features That Matter for Safety

Slat Spacing

Slat spacing must be no more than 6 centimetres (2.375 inches) apart. Wider spacing allows a baby's body to pass through while the head is trapped, which is a strangulation hazard. This is a non-negotiable safety requirement and is one of the primary things to check on any second-hand crib. The traditional two-finger-breadth test (two adult fingers should not fit between the slats) is a reasonable field check.

Mattress Fit

The mattress must fit the crib frame with no gaps at the sides or ends. The standard is that no more than two fingers should fit between the mattress edge and the crib side at any point. Gaps larger than this create a risk of the baby's head or body becoming wedged between the mattress and the frame, which is a serious entrapment hazard. A mattress that was manufactured for a different crib may not fit correctly even if it appears close in size.

Mattress Firmness

The mattress must be firm. A firm mattress does not indent significantly when you press on it with your palm, and returns to shape immediately when pressure is released. Soft mattresses, pillow-top mattresses, and memory foam mattresses are not appropriate for infants: they conform to the baby's face if the baby rolls prone, reducing the ability to breathe. A firm, flat mattress is a safe sleep requirement, not a comfort preference.

Adjustable Mattress Height

Most cribs offer two or more mattress height positions. The highest position is appropriate for newborns who cannot roll or pull up, making it easier to lift the baby in and out without bending deeply. The mattress must be lowered to the lowest position before the baby can pull to stand, typically from around 7 to 9 months. At the lowest position, the crib rail should be high enough that a standing baby cannot topple over it.

Solid Construction and Stability

The crib should feel solid and stable when assembled, with no wobble, creak, or flex. All hardware should be present, correctly fitted, and tightened. Any crib that has missing hardware, stripped screws, or structural damage should not be used. Check the crib's construction periodically as the baby becomes more active and begins pulling up and shaking the rails.

No Drop Sides

Drop-side cribs, which have a side rail that can be lowered to ease access, have been banned for sale in the US since 2011 following multiple deaths attributed to hardware failures that allowed the drop side to detach. If a crib has a drop-side mechanism, do not use it regardless of its apparent condition.

Features That Do Not Improve Safety

• Decorative cutouts in the headboard or footboard. Cutouts can create entrapment points for arms, legs, or the head. Smooth, solid headboards and footboards without decorative openings are preferable
• Post extensions or finials. Corner posts that extend above the crib rail by more than 1.5mm create a clothing entrapment hazard if the baby's clothing catches on them. Cribs with tall decorative corner posts should be avoided
• Attached accessories. Teething rails (plastic covers on the top rail) are a standard and acceptable feature. Attached mobiles that lower into the crib interior, mirrors, or other attached accessories that are not part of the original certified design are not recommended

What to Avoid in the Crib

The crib interior matters as much as the crib itself. The AAP and equivalent bodies in other countries are explicit that the safest sleep surface for an infant is a firm, flat mattress with a fitted sheet only, with nothing else in the crib:

• No loose bedding: blankets, quilts, comforters, duvets, or pillows. These are suffocation and overheating risks. Use a well-fitted sleeping bag instead of loose bedding from birth
• No crib bumpers: padded bumpers, mesh bumpers, or breathable bumpers. The AAP recommends against all crib bumpers for infants. Padded bumpers are a suffocation and strangulation risk; even mesh bumpers have been associated with infant deaths and are not recommended
• No positioners or wedges: products designed to keep the baby in a specific sleep position are not recommended. Back sleeping on a flat surface is the safe sleep position; wedges and positioners add unnecessary objects to the sleep environment
• No soft toys: stuffed animals, comfort items, and similar soft objects should not be in the crib during sleep. They may be introduced as comfort items during waking supervised time later in infancy, but not during sleep
• No sleep aids placed inside the crib: inclined sleepers, infant seats, bouncers, and similar products are not designed for overnight sleep in a crib and should not be used for that purpose

Setting Up the Crib Safely

• Position away from windows, blinds, and curtains. Window blind cords are a strangulation hazard within reach of a crib. Position the crib so the baby cannot reach any hanging cords, even when standing
• Position away from walls and furniture the baby could push against. A crib pushed against a wall creates an entrapment space between the crib and the wall if the baby rolls or shifts
• Use a firm, flat, waterproof mattress cover under the fitted sheet. A waterproof mattress protector keeps the mattress hygienic and extends its life; it should be flat and close-fitting rather than quilted or padded
• Check all hardware after assembly and periodically thereafter. Hardware can loosen with use, particularly as the baby becomes more active and pulls up against the crib rails
• Follow the manufacturer's weight and height limits. Most cribs have a maximum weight or height limit. Transition to a toddler bed when the child reaches the crib's limit or when the crib rail, at its lowest setting, reaches the child's chest height

Second-Hand and Inherited Cribs

Second-hand cribs are a practical option provided the following conditions are met:

• The crib meets current safety standards for your country (manufactured after 2011 in the US, or verified against the relevant standard elsewhere)
• All original hardware is present and the structural integrity is intact (no cracks, splits, or damaged joints)
• The crib has not been recalled (check the CPSC recall database at cpsc.gov for US cribs, or the equivalent national database for other countries)
• A new mattress is purchased for it. Second-hand mattresses carry hygiene concerns and may not fit the crib correctly. A new firm mattress appropriate to the crib's dimensions is a non-negotiable investment even with a second-hand crib
• The original assembly instructions are available or can be obtained from the manufacturer. Do not assemble a crib without the correct instructions for that model

Key Takeaway

A safe crib meets current national safety standards (CPSC/ASTM in the US, BS EN 716 in the UK and EU, AS/NZS 2172 in Australia), has slat spacing of no more than 6 centimetres, a firm mattress with no gaps at the sides, no drop-side mechanism, no decorative cutouts or tall corner posts, and solid stable construction. The mattress should be lowered to its lowest position before the baby begins pulling to stand. The crib interior should contain only a firm mattress with a fitted sheet and a waterproof protector: no loose bedding, no bumpers, no positioners, no soft toys, and no inclined sleep products. Second-hand cribs are acceptable if they meet current standards, all hardware is present, the crib has not been recalled, and a new mattress is purchased. When in doubt about any aspect of crib safety, err on the side of caution: the sleep environment is not the place for compromise.

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This article is for informational purposes only and is not a substitute for professional advice. Always follow current safe sleep guidelines from your national pediatric authority and verify crib safety standards with the relevant regulatory body in your country.