A woman knows she can get pregnant, even if both the man and the woman use all sorts of birth-control. By consenting to have sex, she is taking responsibility for the consequences that action might have on her body.
If she becomes pregnant, it is because of actions she freely chose. If she decides to have an abortion, then that decision is (legally) hers alone. If she decides to give birth, that decision is also (legally) hers alone to make.
That is, the woman (or, perhaps I should say “the pregnant party”) has final say in whether or not to give birth. Since the pregnant party has sole power over that decision in such a situation, which is itself a product of freely chosen actions, the pregnant party is solely responsible for the result of those decisions.
In other words, if a pregnant person decides to have a child, they are responsible for it. The non-pregnant party, having no legal say in the decision to produce offspring, should have no legal obligations to any offspring which are born as the result of another person’s decision.
The only party responsible for the child is the party that had sole discretion over its birth.
This is a non-sequiter. How does “donating” genetic material make one responsible for a child if one did not have a choice over the birth of that child?
Let’s say that I voluntarily give a blood sample for scientific research. A scientist extracts DNA from that sample and clones me. The resulting child, created from my donated genetic material, HAS to be supported by someone. Who do you think bears more responsibility to the child, me, a mere DNA donator, or the scientist whose willful actions brought the child into existence?
I contend that genetic relation is irrelevant in such a situation.