Americans United for Life has rated states on their prolife laws. You can see the rankings and details here.
We can look Here for how the Alan Guttmacher Institute ranks states for "efforts to help women avoid unintended pregnancy". This publication also includes abortion statistics for the states. Granted, it's for the year 2000, so it's out of date, but it's all we have to work with
For 2000, the states with the highest prolife rankings have an average abortion rate (number of abortions per 1,000 women of childbearing age) of 11.4. The states with the lowest prolife rankings have an average abortion rate of 25.4. The national abortion rate was 21. So states with prolife laws had dramatically lower abortion rates than states that enshrine abortion rights in law. If we look at more recent data, from the 2005 CDC abortion surveillance, some states didn't report, but we can look at those that did. Of reporting states, the ones that rate best for prolife laws had an abortion rate of 9.22, compared to a national abortion rate of 15. The states that ranked least prolife in their laws had an average abortion rate of 18. And if we pull in the 2000 numbers for non-reporting states, the most prolife states had an abortion rate average of 9.4 -- still respectable and well below average for the nation. The least prolife states had an average abortion rate of 19.3.
The states with the highest "prevention" ratings from the AGI have an average abortion rate of 19.8. Considering that the national abortion rate is 21, that looks pretty good, prevention-wise, huh? Until you consider this: The states with the lowest "prevention" rankings from AGI have an abortion rate of 14.4 -- considerably lower. If we look at 2005 AGI data, the top states in "prevention" have an abortion rate of 13.67, compared to a national abortion rate of 15 -- which looks nice, until you factor in California. If we plug in the number for 2000 -- the only one we have -- that changes the abortion rate for the states with the best "prevention" to 15.4. If we look at the states the AGI ranks as worst at "prevention" we see an average abortion rate of 13.3 -- lower than the national average.
It's even more interesting to look at California. This state got the worst rating from the prolifers, so it's no surprise that it had a staggering 31 abortions per 1,000 women every year. But what is telling is that the Alan Guttmacher Institute ranks California #1 in efforts to prevent unintended pregnancy! New York, the state that's worst in 2005 data with an abortion rate of 30, ranked 43rd by prolifers because of its abortion supporting laws. The Alan Guttmacher Institute ranked it #5 in prevention! Clearly the Alan Guttmacher Institute gives A's for effort, not for results.
At first glance Wyoming looks like a winner for the AGI -- there were only 14 abortions performed there, too low a number to even calculate an abortion rate. But wait! Nine hundred Wyoming women went out of state for abortions, 9 per 1,000 women of childbearing age. Wyoming is a bit flukey. If we look at the remaining states, we see that Idaho and Kentucky tied for lowest abortion rate -- 4 per 1,000 women of childbearing age. The AGI ranks Idaho #26 and Kentucky #22 in prevention, even though they're the most successful.
American Life League rates Kentucky #12 in prolife laws, Idaho #26.
Granted, correlation isn't causality. It could be that states with low abortion rates also have prolife laws because of a culture that discourages abortion, and states that lack prolife laws also have a culture that encourages abortion. They certainly seem to have a culture that encourages the sorts of "prevention" efforts that the AGI pushes.
But they don't seem to have a whole lot of success.