That’s one question. Another you could ask is whether the state can force someone to give blood or otherwise risk their health to save the life of another person. The impression I get is that most conservatives would say never – except when the first is a woman and the second a fetus. Because without that exception, you would have to treat abortion as a choice regardless of how you think of the latter.
Making the topic as all about the fetus and ignoring the person carrying it is a trick of framing. We don’t do ourselves favors by letting things get distorted that way.