There are over 1,000 children that have already been born, after the performance of this procedure. (from 6,500 IVF cycles) While long term studies haven't been done, it appears to have little affect on the embryo. Google pre-implantation genetic diagnosis. There is a lot of info out there.
What is the time frame of the embryo from which the cell is removed? How old is it in other words? How many cells total?