It would save some lives. I'm not sure of the figure. I believe that it is 20 to 30 thousand a year.
Also It would be a good first step toward more limits. The Gov't would saying that you can't have this abortion because it would mean the death of a baby. It might affect that mushy middle, toward realizing that abortion can and should be restricted. Especially since pro-lifers could show how babies are dying from other forms of abortion.
This is why the pro-aborts are so opposed the banning PBA. They fear it will lead to an incremental reversal of Roe v Wade.
I certainly support a PBA ban but will the lives be saved or will the abortionists just use another procedure?