To answer your question, DChristopher, society should bear some of the burden.

An example where they should: A fifteen year old girl gets pregnant. She made the choice to have sex, so she owns that decision to at least some degree. The guy wants nothing to do with her. She decides to keep the baby. The choice that got her to that place was hers, but I do not think she should be forced to bear the total responsibility for that. Ideally, she has a family that takes care of her and the child. But suppose she doesn't? What then? Society should help her in some way.

Why should society take on this burden? Because there are enough collective resources (human and financial) to handle it, but the girl has virtually no resources to care for the child while simultaneously educating herself and becoming a productive member of society. It's the principle of "from each according to his/her ability; to each according to his/her need."