PBAs were meant to be performed on hydrocephalic babies who have enlarged sculls. In the USA there were just over 2000 performed last year. Congress has twice voted for a federal ban, but it has twice been vetoed by the Senate. I think that it is currently up before the Supreme Court.
As far as I remember PBAs aren't illegal here as it they are regarded as never actually being performed.
I really don't see how a PBA can be justified for the health of the mother, which is the reason given in the majority of cases. And the cleft palate case scares me.