Rando - Agreed, it is often hard to find people to adopt older children, but it is very easy to place a baby for adoption (at least, assuming a healthy baby, which is 90% of what we are talking about here).
CT - It is also nice to hear arguments for "Pro Choice" that aren't completely about wanting to avoid consequences (though many of the arguments listed here are exactly that). The problem I have is that you cite examples of what "could" happen and argue that it is worth aborting instead of even giving the child a chance. Sure, they could end up in a very bad situation, but that's not an absolute. And quite frankly, it's a good lesson to the parents to try to raise the child correctly. I've seen people turn their lives around because they've been put in such a position.
Reverend - Same point as CT. And being a mother is not a punishment. It is, however, a consequence. Remember, there are other options if they don't feel like they are able to raise the child. I really don't see the "hypocracy" that you refer to and I don't think that you do either.
Astranbrulth - Do you have any evidence that there isn't plenty to go around in this world? And I'm not referring to the fact that there are starving people, QED, because there is also a ton of food that goes to waste every year. That's not a problem of supply, it's a problem of distribution. I find your post to be incredibly selfish, which is the problem I have with most "Pro Choice" arguments. An unborn fetus is a human. Perhaps it doesn't have capacity for thought and perhaps it does. We really don't know at what point the spirit enters the body, but ask any pregnant woman when she first feels movement and you might be surprised. You ask me to compare a fetus to a mouse, but I don't know any mouse that eventually learned how to talk and interact, so I have a hard time making that leap.
Spiderman - When you say "primary" purpose, I assume you mean "socially accepted". The bottom line is that, with one exception, no woman has ever become pregnant except through sex. I personally don't think recreational sex is "fine". I'm not saying that sex cannot be used for enjoyment purposes. I'm only saying that the fact that sex is viewed so casually in today's society is an indication of moral decline.
Regardless, this issue isn't about why people have sex, which is a completely different discussion (though I would wager with the same people arguing the same sides for the most part).
Making someone have a baby because contraception didn't work... I'm not aguing extremes. Having a baby is a consequence of sex, not of failed contraceptives. And again, back to the arguement of "they may not be productive", but who's to make that choice. We don't know that they won't be productive members of society either. Remember, my argument isn't to force to woman to raise the child. My argument is that there are other options and adopted children often grow up to be productive members of society...and so do children whose parents decide to give it a go. But I don't know of one case where an aborted child became a productive member of society. And quite frankly, a woman who has an abortion is holding enough guilt that I have to believe that if they eventually do become a mother, that there will be issues that will make them more likely to raise future children poorly (and I'm generalizing here - there are always exceptions). Whereas a woman who accepts the consequences and does what needs to be done to make sure that the baby is provided for (either by herself or through adoption) will be much more able to cope in the long run.
I find it interesting that no one has argued anything on religious grounds. I could do so very easily, but I don't think it is necessary. Things look a bit different with an eternal perspective. I would be interested to know if anyone could posibly suggest a religious argument that favored abortion.
BTW, I do feel that there are times when abortion is appropriate. Where the woman has been violated or where there are serious health risks in keeping the baby. But certainly not just because the woman doesn't want to take responsibility.