Why is it that any surprise at all? Contraceptives are not some lost magic. If he has the technology to mind control, he has the technology to avoid pregnancy.It's quite a fun game. But it's surprising that a super villain who has captured and manipulated so many horny super heroines has so far (and apparently not later) impregnated any of them.
I think that this thing logically still has to come. And then not just at the very end. A couple of hot scenes with pregnant heroines (and also villains) would be awesome.