Say person A has a rare blood disease that can only be cured by running a 9 month round-the-clock infusion from person B. Would we be allowed to hold person B against his will and force him to support person A?
This really depends on whether or not B has willfully taken action that, as any reasonable person knows, can lead to their being hooked up to A for 9 month.
If B is minding their own business and is just kidnapped and forced to act as life support, then I would tend to agree with you, although even there my agreement would be qualified - as I would be coming at this from a utilitarian perspective.
But most pregnancies occur as a result of action that is known, by reasonable people, to sometimes lead to pregnancy - so the scenario you describe does not provide a useful parallel. (It might in cases of rape or sexual abuse, but not in cases consensual sex.)
On it's face, that makes a morally-relevant difference. However, it is hard to see how, by virtue of having irresponsible sex, thereby creating the foetus, the mother can be seen to be committing herself implicitly
to carrying the foetus to term. At the time of the intercourse, the foetus doesn't exist. How can it be a party to a contract, even an implicit one?
The foetus may or may not be morally human. In neither case does it give the foetus the right to life as an unwelcome parasite on the mother.
You seem to be implying here that parents do not have any special moral obligations towards their children. Am I reading you correctly here?
Not quite. I am making a critical diffence between moral
obligations, and legally-enforceable ones. For example, we are morally obligated to help a friend in need. But unless we contracted to, we ought not be legally-forced to do so.
Caring for your children (as well as your parents and possibly more remote relatives) is clearly a moral obligation. I don't think it should be a legal one.
At later stages of pregnancy, I would support requiring (to the limits of medical technology) keeping the foetus alive - in other words having a premature birth. The new-born baby could then be handed for adoption. Before viability, however, neither the foetus nor society on her behalf has a right to FORCE the mother to carry her.
So, if I understand you correctly, a woman would be within her rights to have labour induced at, say, six months, and the premature baby could then be cared for by someone else and handed over for adoption?
Who, if anyone, would have the moral obligation to pay for the extra medical care this baby will require?
Hard to say in the abstract. As noted above, the mother may well have had a moral obligation to. Possibly the father. Perhaps a well-off relative. The question of moral obligations is subjective, and can have a different answer to different people sharing a society.
That is very different from the issue of legal obligation. Under normal circumstances, I don't think any member of society should be legally
required to take care of another (either directly or indirectly by being taxed to do so).
Experience clearly shows that in any moderately-affluent society, there is never shortage of people willing to help the needy out of charity.
Moreover, in all democracies I am aware of, the state currently provides financial assistance to orphans, and even less-clearly-deserving people. That state action presumably reflects the attitudes of the majority in society. With the majority clearly indicating their willingness to help people in need, I can see no circumstances under which charity will be lacking in a free society.