No. There's a proportionality rule in self-defense which generally does not allow lethal force to resist non-lethal attacks. I can't shoot someone in the chest or head who is about to punch me in the stomach (though if I'm good enough to aim for the leg, that might be legal). Of course, a punch to the stomach of a pregnant woman does much more harm, and so it may very well be worth codifying that as an exception to the usual proportionality rule.