This is a fallacious argument until you grapple with the reality that no HUMAN has the right to use another HUMAN to sustain life. It doesn't matter if a person is a fully grown adult that can cure cancer and world hunger, or a 1 year child. That person does not have the right to use another person to sustain their own life under any circumstances.
You are arguing a strawman. The question is not if the fetus is "human" or "life".