Should a woman be kept a live on life support if she is pregnant until the fetus becomes viable?

Should a woman be kept a live on life support if she is pregnant until the fetus becomes viable, regardless of the gestation, and or regardless if she has an advanced directive?

Please remember, you need an ethical theory and three ethical principles to support your thesis and one theory and two principles in opposition to your thesis and this needs to be reflected on the outline. You cannot use the same theory & principles for both.