Babies are delicate, which is why choosing the right crib mattress is one of the most important decisions you can make.

Almost all cribs use standard, U.S-sized mattresses. It's important to purchase them new – and make sure they are firm. Some studies link softer mattresses to sudden infant death syndrome or SIDS.

Some other custom sizes offered for this online mattress are wider with the same length: 33 inches and 36 inches, giving shoppers a few options when it comes to smaller mattresses. Cribs and toddler ...