I'm all for taking responsibility for your actions, but that's too simple a question to get valid responses from.
A man and women are 50% responsible for creating a child, but currently in society, it is not an equal decision, and it depends on where you live and mainly comes down to money. (Men currently have more decision power in less than democratic societies {i.e, they still own women}, but have less decision power in more democratic ones, barring wealth.) I think it should be equal for everyone all the time. No more treating women as chattel, but no debtors prison for child support either.
But go ahead and apply the societal differences (that are real world examples) to all the following more involved questions. What about rape? Incest? Affairs? What about if an older woman gets pregnant from a minor boy? What if a DNA example is not determined until after the child is a few years old? (Divorce, Adultery, Adoption, or as it has happened in real life, fathers have been forced to pay or even chosen to pay even though the child is not genetically related.) What if the pregnancy prevention methods didn't work (I'm assuming both consenting adults engaging in sexual activity didn't want a pregnancy and were actively using one or more forms of birth control) and afterwards the woman decides that she wants to keep the child, but the man doesn't, or even can't afford it? What if that situation is reversed?
What if the participants are not actually knowledgeable about sex, or birth control? That happens in even modern societies.
There are too many real world variables for this simple question to accurately answer it in a poll, and none of them have simple answers.