Doppler / frequent & 3D ultrasounds

Dalva
No hate just genuinely curious because I see a lot of moms on here getting frequent ultrasounds including some 3D ultrasounds already and using at home Doppler frequently.
I know some moms have had MCs/are high risk that may require more US appts but in general aren't any of you concern about the potential risks to your baby with exposing them more frequently to US or Doppler regularly?
Obviously common sense and historical data, research says all of these things are generally considered safe but there are still so many unknowns and plenty of scientific evidence that frequent exposure does alter babies tissues even in a small way....
Again, just genuinely curious everyone's take on these risks since I see it a lot on here....