Legalized pot: great idea. Legalized gambling: ditto. Legalized prostitution: ditto. "Sins" have no business being criminalized; they should be monitored, controlled, taxed. 
A woman's choice over her pregnancy is not a crime, it is a bio-logical fact. Her body, her fetus, her pregnancy. To those who seem to feel there is some religious necessity: remember that a significant number of pregnancies fail through miscarriages--- including many in the last trimester. Is "God" a murderer/murderess? 
Only the pregnant woman knows her reasons, whether her physical or mental health or other. There is no easy solution to this question but the least onerous, the most democratic and least "big brother/big government" is to let the woman and her doctor make the decision. The rest of us and our government need to respect women and their most difficult decisions.