‘We cannot let Bob change the subject.’
changing the subject is the only option left to a pro-choicer when it comes time to debate...
I have noticed a particularly vicious tack being taken in the sundry sites I frequent, many featuring secularist thought and philosophy, and it seems to be pushed by young females; they claim that a baby growing in the womb is actually an affliction to the mother, leeching vital nutrients from the mother and causing sickness and pain...thus, they say, the baby is in the position of interloper and attacker, and as such the mother is perfectly justified in ridding herself of such affliction, as an act of self defense...
Just point out that anyone who tries to paint a member of their own species, in fact, their own child, as a “parasite” is exhibiting signs of a sociopath, and suggest they seek professional help.