There is the fact that making abortion illegal is incredibly dangerous as mothers in desperate need of having one do consider home abortions or use an illegal back street clinic (source a) which can be incredibly unsafe and possibly lead to infection. There is an argument by pro abortionist that by making abortion legal, it would significantly reduce morality in woman, yet anti-abortion groups claim that keeping abortion legal would increase the amount of crime.
The main excuse pro abortionists (source b) use is that it should be up the mother to pick what happens to her baby as, until it is born, it is part of her, and she has every right to decide what happens to it. Another excuse which is used by pro abortionists is that life begins when brain activity begins, which is in the much later stage of pregnancy and that if the mother wishes to remove the foetus before this happens, then it cannot count as murder. One more argument, pro abortionists use, is that there should not be influence made by religion in any way and that it should be only be allowed with the permission of two doctors whether to abort the birth or not.
The core argument made by anti-abortionists (source c) is that, to kill a foetus is to end life. Catholics believe that life begins straight at the point of conception and thus, murder. Another argument, used by anti-abortionists, is that every baby has the potential to contribute largely to the world. Anti-abortionists often use religion on the bases of their arguments, and use bible quotes to justify their claims. Jeremiah 1-5: "Before I formed you in the womb, I knew you, before you were born I set you apart" This quote is an example of god telling us, directly, that abortion is wrong.
Abortion can be incredibly dangerous for a woman; any mistake can be fatal and in some cases may even result in death. In many cases, the process of abortion has left the mother infertile and/or left the mother with extreme emotional problems. In my opinion, I believe abortion creates just as many problems as it tries to solve.
Overall my opinion on abortion is that it should be purely up to the mother what they should do. Abortion is a personal thing and the decision to go through the process should not be influenced by anybody. I do not believe that religion should make abortion laws in any country, as it can affect the population, culturally.