It is a very serious decision, but sometimes a woman just knows that she is in no way ready to give birth to or to support and nurture a baby. So if she is responsible, she takes birth control measures. However, no birth control measure is absolutely fool proof and that is why abortion must be a legal and moral option in case contraceptive methods fail.
If you are not ready to have a baby, then don't have sex. Or at least make sure you are educated enough on contraceptive methods. If those fail, which may sometimes be the case, the pregnancy will have to be dealt with. And if you have sex after marriage it shouldn't be a problem. I believe that abortion is only acceptable when the baby's life threatens the mother's life or if the fetus is diagnosed with a severe or deadly illness before birth.
I believe that abortion is utilized like this way to often. Having an abortion is a negative experience no matter what the circumstances are or where you get it. The way that it happens it is hard on your body and the psychological effects of it are usually worse than that. So even if the procedure goes well then it is still harmful psychologically.