Anyway, I find people's thinking around the morals of abortion to be quite fluid . The termination rate of pregnancies with chromosomal abnormalities far exceeds the percentage of people who identify as "pro choice" and cannot be explained simply by pro-choice people being more prone to fetuses with such conditions.
There are plenty of pro-choice arguments, but this is not a very good one.
Coercion is often justifiably used when lives are at stake. For example, the government might "force" sick people in a quarantine given an epidemic outbreak. What you want to show is that the fetus is not a person and, therefore, doesn't have the same rights as the mother. This is difficult, but not impossible -- although there are some concessions that need to be made along the way.
Says the person who has the need to argue about what women can and can't do with their bodies while not having a uterus himself.
I can make these kinds of arguments by analogy or generalization. So I hope you can see how (and more importantly why) we can think about morally-difficult problems like abortion even though we're not women, war even though we're not soldiers, etc.