If you look around the world, abortion rates are lowest not where abortion is illegal, but where contraception is widely available and there is social pressure to use it. Even with all the division in the US over the abortion issue, I know quite a few individuals who consider themselves strongly "pro-life" and who are also very strongly in favor of contraception.
Yet, I have not been able to find any "pro-life" organization or group that is pro-contraception. "Pro-life" groups are willing to say that abortion is murder, that pro-choice advocates are baby-killers, that Roe v. Wade is like the Holocaust, that abortion is the defining moral issue of our time. This is extremely strong language, and only acceptable if you really mean it.
If you do mean it, you have a moral imperative to promote contraception. If you believe that birth control pills and IUDs are also infanticidal, that only increases your moral obligation to promote barrier methods such as condoms.
Pro-life groups don't approve of contraception, but surely it isn't worse than what they characterize as mass slaughter. If the lesser evil of contraception prevents countless murders, you'd better encourage it for the sake of the greater good.
I've putting supporting links and additional arguments here in my LJ. If you like this approach, feel free to use my wording in LsTE to your own local or national newspaper.