Prochoice ideology is fundamentally an argument that society should not enforce morality, or even judge others for being immoral.
Abortion advocates will do their best to to disguise this axiomatic foundation of their position, but because their beliefs are not grounded in moral principles, they have a hard time obscuring it. Since they have abandoned morality as a principle that one should be motivated by, and are instead trying to deceptively manipulate your moral values by wrapping their true position in the language of women's rights, they do a poor job of keeping the mask from slipping.
They will make lazy false assertions that: no one has a right to the invasive use of someone else's body, to appeal to your sense of morality around rape or forced organ donation by conflating gestation (which is the age appropriate standard of care that all children deserve, and is a necessary evolved function of human reproduction that all living humans require) with immoral transgressions against you to obscure the reality of what they really want: permission to kill their own children.
They will argue that killing your own child is a necessary choice women must be able to exercise to protect women's rights, while at the same time saying that society should permit the killing of female children through abortion which deprives other female humans all their rights. This contradiction occurs because they are not starting from a foundation of morality or first principles, they are starting at their selfish desire to avoid the burden of caring for their own dependent offspring, and then working backwards to justify it by co-opting the language of morality to disguise how monstrous and evil their position really is.
If you press them on why unborn children should be a special exception to the parental obligation of providing the age appropriate standard of care that we expect for all other children, they are backed into a corner because the don't have a principled position, and so they will either cite their personal opinion that because the care for unborn children is different than that of born children, they don't think it should be required because it requires more of a burden.
Some of them will even abandon the pretense of morality all together. If you ask why does a mother have an obligation to breastfeed her newborn child if she gives birth all alone in the wilderness and has no formula, and its the only way to provide the age appropriate standard of care to them, they will say there actually is no obligation to breastfeed your child in that situation, and they will demand legal citations from you to prove there is one.
This happens because parental obligation is a principle of morality, and they have abandoned morality. All their objections attempt to presume that they are operating under the same moral values that the rest of society has, but its just a ruse, they don't care about morality; they just want the freedom to be immoral even to the point of killing their own children.