I am not a lawyer, so you may need to be a little more explicit with how it does work for my benefit.
When a person experiences circumstances which the result of another person's negligence, then the negligent person owes a duty to the other person to restore the
status quo ante -- the affected person's circumstances before the negligence affected them. The problem using this to try to object to an abortion are numerous. 1.) a zygote/embryo/fetus is not a person, 2.) the fetus did not exist when the allegedly negligent act took place, 3.) the fetus' circumstances are only improved as a result of the sex, 4.) the
status quo ante for the fetus was that it didn't exist, and abortion is in fact the perfect solution to achieve that.
Your argument seems to stem from the uniqueness of the state of pregnancy as it relates to other matters rather than any form of true precedent.
I don't know where you would get that idea, since my arguments are based upon well-established legal principles.
And, to your automobile accident analogy, we do not consent to automobile accidents, but automobile accidents are very very rare, and not the normal outcome of driving. If I have sex every day for a year, it is almost guaranteed a pregnancy will result. If I drive every day for a year, it is still very unlikely that I will get into a car accident. The rational expectation of an outcome should be part of the consideration.
This is merely a difference in degree and not a difference in principle. I would think it's easily agreeable that usually the expectation when having sex is that pregnancy will not result, and the statistics support that.
I think child support might be a better comparison. I believe it would be closely related to the legal duties of a father to support the child of a mother. Is the father not legally obligated to support the child due to his consent to participate in sexual intercourse?
No, the father is obligated to pay child support
to the mother because he is the biological parent of the child. It is not a matter of consent.
If the father has a legal duty due to his participation in intercourse, would that not be an example of a legal duty to a party that does not yet exist?
Monetary child support obligations are to the mother, as a consequence of being the child's biological father, not because he consented to the intercourse, strictly speaking.
As to the life support agreement, I think you may be wrong. Is a hospital allowed to refuse to provide life support to a patient that is brought in because they will not be able to pay their bills or they cannot prove insurance coverage?
A hospital is not a natural person, compromising the very integrity of its body to supply such life support.
In fact, I think that if I begin to give you CPR, I cannot stop until either help arrives or I am no longer capable of providing assistance. I know they are not perfect analogies, but again this falls back to the very fact that pregnancy is a unique state.
I don't know that to be the case, but regardless giving CPR does not involve the same type of violations to bodily integrity that pregnancy does.