Quoting Mom-moo:" If god forbid such a thing happened, a mattress cover wouldn't prevent it. Try not to obsess over it. Sending you good thoughts!"
Quoting The Blissful Six:" SIDS is not preventable. You can supposedly lessen the chances of it happening by following certain guidelines. ... [snip!] ... in a crib with no thick blankets or bumper guards. Your best bet is to stop worrying or invest in some kind of sensor monitor."
Quoting Catrina [+2] ♡:" I have the AngelCare movement monitor. "