I have crib bumpers in my daughters crib. She's been sleeping in her crib since 4 weeks old. They're not the mesh ones either. If it wasn't for the bumpers..She would have smacked her head so many times. It's debatable. Some say they're safe...others say it causes SIDS (everything "causes" sids now). My daughter is 7 months old and I've had no issues with her suffocating. She even sleeps on her tummy which is another "sids" cause.
It's been proven unsafe ! It was said on the radio . Nothing in the crib with them
Safe in my opinion. Keeps them from bumping their head