3. If mother got pregnant accidently via one night stand and she doesn't want baby, then abortion is probably okay, probably, because child will suffer from growing up without loving parents and most likely she will be abused by a mother or stepfather. But this part is very debatable and I don't have fixed opinion about that. There are cases when mother doesn't want baby but grandparents take it as their responsibility to grow them, so, it's very debatable.
Yeah amidst all the valid points and very brilliant indeed, this happens to be debatable just like you also agreed on that. For me if couple mistakenly get pregnant when they are not planning it or one party tricked the other to get it or it is just honest accident, I don't believe that they will transfer hate or agression to the baby so long the baby is not physically challenged what so ever. I have seen couples who end up loving their "mistaken" child more than the rest. Like I don't know about couple that will hate a child that is physically okay and mentally sound just because the child is "mistakenly " conceived or couldn't eventually aborted when they tried to remove it.
I totally agree with the first and second points raised by Shield123, in the cases of rape, early detection of child defect in the womb can be morally accepted reasons for abortion, because they're not the choice of the mother. Like you, I don't quite agree with number 3, because if a woman has a consensual sex with a man, without protection and it later results in pregnancy, I think that it'll be morally right to accept the outcome of the act, since it's a life that is involved. I also think that the unborn child has a right of existence and should be given birth to, so the mother or parents will face their responsibility of raising the child. But I must confess that this is not easy because there is possibilities that such a child might be born into suffering and neglect where he or she can never experience the joy of proper upbringing, because the mother or parents were not emotionally or financially ready to carter for a child. So in the end whether abortion is morally or religiously not right or acceptable, it should come down to the choice of the mother, because she carries the pregnancy.
