Cats and babies

I am currently 5 weeks pregnant, ( I have a long way to go) and I have two cats at home there names are Alex (calico) and Xander ( black and white). They are very good cats but they have never been around babies. Someone brought it to my attention if I was worried that they might try to scratch my little peanut when he or she arrives. I honestly don’t think that they will do anything to the baby, but you never no. Anyways I’m just wondering if anyone no any techniques that will help introduce the cats to the baby when it comes?