Does not work of she knows who you are
Perhaps you should think about that beforehand, assess whether you are willing to take that risk. It is definitely an option she doesn't have, at least when it comes to being stuck being the only one of the two people who created the person being responsible for them financially.
If she aborts or has a miscarriage, no child, therefore, no financial responsibility from the man needed.
If she has the child, then gives it up for adoption, either lying or getting the man onboard to sign, or she simply doesnt know who he is, he again still has no financial obligation.
If she even just drops off the child at a safe haven, he again has no financial obligation, unless he chooses to take it on at that point, after.
So when it comes to being forced into financial obligation, when she decides to raise the child, it would be either he pays a certain portion, normally less than half (that is the average for child support, less than half the cost of raising a child) or he pays nothing because he ditched and she is raising the child alone (may get help from society, through welfare, depending on if she qualifies). There is no option here where he pays and she doesn't.
What that means is this is really about revenge or shirking responsibility, some men just want to live their lives without the consequences. In the case where some are in it for revenge, it is based on "well she can choose to abort my baby so I should be able to choose something completely different, really the opposite of what I'm complaining about her doing".