Can Acoustive Wave Therapy cause birth defects if you undergo treatment while pregnant?

I had 6 Acoustic Wave Therapy treatments performed on my abdomen over a two-week period. It was not until after the treatments that I found out I was pregnant. I have not had any treatments since but I am worried about the harm those treatments may have caused my embryo/fetus. What could the risks be? I am especially afraid that the procedure could cause some sort of deformation.