And what of the future value lost of the person who does not want to carry a child to term? Who loses value in their life by trying to pour that value into a fetus.
The problem is the argument about value loss is extremely utilitarian; while proving definite value is basically impossible, one could imagine a scenario where the overall value of a two-person system goes down. In this case, abortion would be morally imperative to reduce suffering/increase value.
Utilitarianism is not very human, and shouldn’t be used to make conclusions about human ethics.