Baby Bjorn Mattress Topper for Baby CribA mattress is always included when you buy a baby crib from BabyBjrn. But if youve inherited a crib or got one secondhand, a new mattress topper is an easy way to freshen it up. An extra mattress topper can also come in handy if the old one is worn out or youd like a spare for laundry days. Please note: For your babys safety, always use only one mattress in the crib at a time.