I know that a fish finder can be uncomfortable if you get to close to it when you are in the water so I would assume the same is true for an ultrasound...
I just know the one ultra sound we had done before our daughter was born made her scoot away as fast as possible. I asked my Ob about that and he allowed as how while he did unltrasounds he wasn’t real fond of them. He said they tended to be done too early and too often during the pregnancy. We don’t have a lot of history with these devices but I do not an increase in autism cases with the increases use of ultrasound ——is that casal? Have no idea I just know that the increase is there