Unexpected children (i don't like to use the term unwanted in this case, but it might have been accurate before I met my daughter), do not have to lead to welfare or any other such thing.
Having an unexpected child lead to welfare or more dependence on the state happens to irresponsible people.
The folks who are responsible who have an unexpected or unwanted child do what I did... they do whatever it takes to ensure that the child grows up with what he/she needs without burdening others.
I was making very low wage as a help desk jockey at a school system, playing rock and roll in my spare time, when Amanda got pregnant.
When she got pregnant, rather than stay in that position and accept welfare and other gov subsidies, I volunteered for another term of active duty, used my spare time to advance my education, and moved myself up in the world.
Throughout the past few years i have CONTINUED to position myself well for advancement and have worked my ass off in that effort, in order to ensure that I make enough to afford private schooling for Brooklyn. I now make 92k a year.
There are costs. I work my ass off. Yesterday and today both were 12 hour days. I travel a lot and miss my family terribly when I go.
Not sure if this is relevant for the debate, but my point is that an unwanted or unexpected child only becomes a liability to others when the parents of said child allow it to be so.