Safely tucked in the bottom of your crib and hidden underneath your carefully chosen crib bedding is the crib mattress. Of all the nursery items you have to think about and purchase, the crib mattress is given the least amount of thought. Crib mattresses may all look alike: small, firm, covered in vinyl, decorated in bears and bunnies -- but not all mattresses are created equal.
There are two major types of crib mattresses: polyurethane foam and innerspring.
Foam mattresses are made from a foam core covered in a single layer vinyl cover or a quilted vinyl cover. Innerspring mattresses are made of multiple layers, including coils, border rods, insulator pad, cushioning, and a cover.
Both foam and innerspring crib mattresses have a single layer cover or a quilted vinyl cover. High-end crib mattresses have a double or triple laminated cover, nylon reinforced vinyl cover, or hospital grade vinyl. Nylon is one of the best and most expensive covers. Nylon covers allow the vinyl to stretch to a greater degree without tearing than other vinyl covers.
Most high end mattresses include vents on the sides of the mattress. There are two types of vents: standard and eyelet vents.
Standard vents are two large vents placed on each side of the mattress. Eyelet vents are smaller and usually run around all edges of the mattress. Mattress vents are a bit controversial. Some people really like them and some people don't. Vents allow the mattress to breathe by allowing air to move in and out of the mattress freely. This prevents the mattress from popping like a balloon when your baby jumps up and down in excitement.
Vents can also allow airborne particulates to enter the mattress. Although the vents are nowhere near your baby's face, some parents are uncomfortable with the proximity. You must decide for yourself whether you like or dislike the idea of vents. If you are buying a high-end crib mattress you may not escape them.
All crib mattresses must be treated with Boric acid or other chemicals to meet federal flammability standards and to make them wet resistant. Even crib mattresses which claim to be "all natural" must be treated.
Your crib mattress will include a manufacturer warranty of varying length. Some manufacturers guarantee their products to be free from defects in workmanship and material under normal household use and service for 1 or 2 years following the date of purchase. Most exclude ripped or torn vinyl from warranty coverage.
Your baby will be sleeping on this mattress for the next 2 to 4 years of their life, so you want it to be the best quality mattress possible. Your baby will be spending upwards to 70% of their lives on this mattress as an infant, when their bones are the softest and growing faster than at any other stage in their life.
There is no proof that an innerspring mattress is better than a foam mattress -- it is the quality of the mattress that matters most. A high end foam mattress is better than a low end innerspring mattress and vice versa. Many parents prefer the familiarity of an innerspring mattress, but a high quality foam mattress can offer the same level of support for your baby. A firm, quality crib mattress will give your baby the extra support and provide the safest resting place at a time when this matters most.