Hello, I would be happy to help you today.
Amniotic bands are uncommon. They represent bands of tissue made up of the same tissue that makes up the fetal sac. These bands can cause problems, sometimes referred to as 'amniotic band syndrome'. Given the description that they look "minor" and that the baby is "moving freely" is very reassuring. The reason they are saying this is that there is a concern if a fetal arm or leg is impinged by one of these bands in a way that inhibits development.
Personally, I have seen this many times, and in no case has it presented a problem. In general, the patient was followed with
ultrasound at regular 3-4 week intervals. This is a way to assess growth, potential issues with regard to the band and how it might be affecting
fetal movement, and to assess the fetus' position at the end of
pregnancy.
Based on what you are saying, I would not be too worried. Ask your doctor what the followup is going to be in terms of ultrasounds. If they are not seeing a potential problem at this point, it is very unlikely to develop later on.
I hope this helps and good luck!