No, the baby is incapable of performing such acts.
Rather, the process of pregnancy - caused by the mother's (and not the baby's) choices and actions - can, rarely, have harmful side-effects on both the mother and baby.
This:
> Killing X would decrease my own risk of coming to harm.
does NOT imply this:
> X is to blame for posing a threat to me; I may justly respond with self-defense.
For example, if you're ship-wrecked and end up on a life-boat with another passenger, killing that person may decrease your risk of running out of supplies before you're rescued, or the risk of him getting sick and unwittingly infecting you, etc. etc. In other words: Killing them = less health risk for you.
But killing him would still clearly be murder.
And it wouldn't be made any better by saying....
"Unfortunately [he]'s still more than capable of sickening or even killing [me]"
"Disagree that [other passenger] is innocent. [He] is a constant threat."
...and all the other vile rationalizations made in this threat.