At the moment, according to the Guttmacher Institute which collects data on birth control and abortion, nearly half of all US pregnancies are unintended. Of those, 40% end in abortion. That's WITH the negative propaganda on abortion--50% of people in the US describe themselves as "pro-life." Guttmacher's stats say that 61% of the women who have abortions in the US have another child already.
In spite of the fact that so many of us disapprove of abortion, we have the second highest rate of abortion per capita in the world, and more than half of the people who are getting abortions are doing so because they have gotten pregnant by accident and already have another child or children.
What was especially telling to me about these stats was that 54% of the women who had abortions had been using contraception in the month before they got pregnant. Most used it inconsistently or incorrectly. A lot of the women who were not using contraception reported that they considered themselves at low risk for getting pregnant.
Yes, I think it would make a very big difference if we had better access to contraceptives and to information about contraception.
Again, this is an issue of public policy, not one of individual ethics. If you want fewer unintended pregnancies, go with funding for family planning.