Marginal cord insertion

Went in for the anatomy scan last week and was told I MIGHT have a marginal cord insertion. Dr didn't explain anything about what it is, or how it's caused or what are the risks. Just said I would need to see a fetus diagnostic specialist. Has anyone else gone through this, & what did you do through the rest of the pregnancy? How is the baby? I read a bunch of stuff online which freaked me out.