There are two general types of crib mattresses: foam and innerspring. Both tend to keep their shape well. There are differences, of course. For one, foam is lighter. The densest foam mattress is usually no more than 10 pounds, compared with 20 to 25 pounds for some innerspring mattresses. So changing your baby's sheets may be easier with a foam unit. Foam is also less springy and therefore less apt to encourage your baby to use the mattress as a trampoline. Still, innerspring crib mattresses remain the most popular.
If you're considering a foam mattress, keep in mind that low-priced models tend to be mushy and flimsy, with a thin vinyl covering and vinyl edging. They may also be unsafe. Putting a baby to sleep on a soft mattress increases the risk of Sudden Infant Death Syndrome (SIDS). Higher-priced models tend to be firmer (and therefore safer), with thicker, reinforced vinyl or cotton coverings.
To assess foam density (which has a direct relation to firmness), compare the weight of different foam models. That's not always easy to do in a store, but if you're able to lift several different mattresses, do it. In general, the heavier the foam mattress, the denser the foam. You can also give the mattress a squeeze test in the center by pressing your palms into both sides of it at once. A dense mattress won't allow you to press very far. A denser foam mattress is also likely to have firmer edges, which is another important performance factor.
To judge the quality of an innerspring mattress, don't go by the sales gimmick of "coil count." While the cheapest innerspring baby mattresses have about 80 coils and the most expensive can have 600 coils, a high coil count doesn't always mean a firmer mattress. In fact, a model with 150 coils can be firmer than one with 600. You can judge by picking up mattresses to compare their weight and by squeezing them to test for firmness. Innerspring models generally have firmer edges than foam mattresses, but squeeze the edges to do a comparison. You may also feel border rods at the top and bottom perimeter, which provide extra edge support for safety and durability.
The number of layers of padding, what that padding is made of, and the quality of the covering add to the price and increase comfort. The cheapest innersprings, like low-end foam mattresses, have thin vinyl coverings and edgings, which can tear, crack, and dry out over time. As prices go up, coverings become thick, puncture-resistant reinforced double or triple laminates, and edgings have fabric binding, which is a sign of quality. Beyond that, reversibility, the presence of ventilators, and thickness are factors that differentiate one model from another.
The mattress you select should also be in compliance with a new flammability law that went into effect on Jan. 1, 2004. Though this is a state law applying only to California, crib mattresses sold in other states are expected to comply with it.
SHOPPING SECRETS
Compare mattresses in the store. Do this by squeezing them.
Confirm store return policies. And keep your receipt. A store's return policy is more important than a mattress maker's warranty. The store should be willing to exchange a mattress that doesn't fit properly, which is a major safety concern.
WHAT'S AVAILABLE
The major brands of foam and innerspring mattresses are, in alphabetical order: Child Craft, Colgate, Evenflo, Kolcraft, Sealy, and Simmons. Prices range from $30 to about $230.
RECOMMENDATIONS
You don't have to spend the most to get a good quality mattress, but don't skimp, either. A budget somewhere between $90 and $150 will generally serve your baby well. A good, firm mattress may also promote proper posture and is more likely to be durable, which is important if your baby will be using the same mattress as a toddler bed or you'll be passing it down to future siblings.
In the case of innerspring models, look for a firm mattress with good support from border rods. Border rods provide extra firmness, durability, and edge support. A mattress with reinforced or embossed vinyl is leakproof; it is also less likely to tear on the metal edge of a mattress foundation and should hold up better over time. Also look for air vents along the sides of the mattress, which not only help keep the mattress ventilated but may prevent seams from splitting when your tot inevitably starts jumping.
When selecting a foam mattress, go for one with high-density foam. Do the squeeze test for firmness in the center and at the edge. Pinch the mattress covering or ticking; it should feel thick, not flimsy.
Make sure any mattress you buy passes the two-finger test for fit in the crib. That is, if you can place more than two fingers between the mattress and the crib, the fit isn't snug enough. Check that fitted sheets fit snugly and securely, overlapping the corners so that you can't easily pull them up at the corners. Ill-fitting crib mattress sheets are a strangulation and suffocation hazard. And never use an adult sheet as a crib sheet, not even in a pinch.