You really cant force anybody to carry a child to this world. No matter how ugly it gets, the child is integrated in the womans body and she should be able to remove it.
If there was a way to transfer that unborn child in to somekind of artificial growing chamber, then it would be another issue. But as long as state doesent own our bodies, everything that is within is nobody elses business. Even if the child were fediddleing talking and singing in the stomach, it has no right to be there if the mother chooses. If it cannot survive outside the womb, its not the mothers problem really. As long as it is lawful to breed without restrictions or signing any papers, this is what you get.
This is where our marshmellow candybar fairytale western lifes meet natures reality, we have come far with our abilities, but still have to hatch the new human beings inside women and give birth in the way every other mammals do.
Actually there is no child until the woman gives a birth, before that there is only the mother with uncontrolled cellgrowth in her stomach. Yes, that could be also taught as a cancer, depending how you like to view it.
About the rape + miscarriage = murder, it is not relevant about this subject, you can argue it separately. That habit of ruling do not define the standpoint of abortion.
ps. Yes i am cynical ass**** and deserve to be shot, but try to argue my point.