Man, that's rough. I know all about worrying for your child, but not so much for your reasons.
I think the simplest thing to say is that even if you didn't have MS you would constantly worry about the health of your children. I know I do. I pray every night that my son remain healthy. We know people with children who have cancer, or have suffered life altering injuries, so each day that he is okay and "normal" is a blessing.
Enjoy their time in childhood. It is really all you can do. Support MS research, of course, and hope that they find a preventative before any of your children show any symptoms. But don't let fear ruin their childhood for you. And even should one of them show symptoms, don't allow guilt to ruin you. You are not responsible for your genetics! And I think your children will not blame you, let alone wish they had not been born.
I don't know you well @gmuxx, but I know you are good people! Take care of yourself so you can take care of your children. Show them all the love in your heart. Take precautions, but don't let fear of the future ruin the now.
Be well sir!
Thank you for your words.