I believe that women and families have the right and responsibility to control the timing and number of births. Contraceptive methods that cannot reasonably be construed as abortion (e.g. hormonal contraceptives, intra-uterine devices, condoms) are generally available in the West and other relatively wealthy countries.
However, hormonal contraceptives and condoms have ongoing costs. Ideally, condoms shouldn't be used as ongoing birth control. That leaves hormonal contraceptives. However, to the growing number of people in the US who are uninsured or underinsured, the ongoing costs of contraceptives can be a barrier.
A recent Chicago Tribune article discusses family planning in a recession. The picture isn't good. One woman decided, with her husband, to end her pregnancy as they couldn't afford it. Ironically, affording the abortion, which was not covered by her insurance, was also a stretch. One Planned Parenthood clinic interviewed said that January was a record month for abortions (although one month at one clinic isn't necessarily conclusive, it's not a stretch that a similar trend could emerge nationwide).
Adoption agencies and the National Network of Abortion Funds (which provides financial assistance for abortion) reported increased demand for their services. In addition, women are waiting until later in their pregnancies to get abortions, as they need to raise the funds.
Another Planned Parenthood clinic reported that women were seeking longer-acting contraceptives. A monthly supply of birth control pills costs my fiance, who is insured, a $10 copay (copays are a flat rate one pays with medication or medical services; they are a form of cost-sharing). Our income at present is low as we are both searching for permanent jobs; $10 monthly is not an insuperable barrier now but it could be if our wages remain low.
However, many poor families are uninsured and will face a higher cost. That cost could be a sufficient barrier to them that they might switch to condoms or not comply fully with the medication regimen. However, either of these will increase the chances of pregnancy.
The folks who say they would like to ban federal funding for Planned Parenthood have yet to present an adequate solution for poor women and families. Frankly, some of the anti-abortion crowd would be inclined to let them starve. I think all of us would rather that families not be forced to resort to abortion. It is a difficult decision for everyone, contrary to what some might think.
To help reduce the number of abortions, the US needs an adequate safety net that delivers a reasonable amount of cash and non-cash assistance (the latter might include food, housing, childcare) and ensure that jobs at the bottom are delivering an adequate wage. The best way to do that is through provisions like the Earned Income Tax Credit and the new Making Work Pay credit.