Good Lord NO!
They don't even have teeth yet.
If they have bad enamel DNA there's nothing you can really do until they're older to prevent cavities, they'll have a mouth full. If they get good enamel DNA then they won't have a single cavity even if they never brush their teeth or even swish food out.
I took one of my guys to almost every dentist in town. His father wanted a dentist to tell him he needed to brush his teeth every day in the morning and in the evening. Not one dentist would tell him that. They each said they had never seen such perfect enamel. SO the dad kept getting mad and still sent the man to more and more dentist.
He never had a single cavity in his whole life. He didn't ever pick up a tooth brush.
That's what can happen if good enamel DNA is present. Then there's that kids who brushes, flosses, rinses, goes to the dentist twice a year for cleaning, etc....who has to have fillings every time he sees the dentist.
If you get good DNA you have good teeth, if you get bad you get bad teeth.
So don't worry so much. Look at your teeth and hubby's teeth. Taking good care of the mouth isn't a bad thing but overdoing it won't help one way or the other.