Imagine that there is a married catholic couple, one that doesn’t want children.
Maybe they already have all the children they could want, maybe they would rather focus on their work, maybe they don’t think they would make good parents or otherwise don’t trust themselves to raise a child, or maybe they don’t have the resources to raise any/ any more children. But for whatever reason, they do not want to raise any more children.
They are not using contraceptives because the church disapproves of it, but they are also not using NFP because they still desire the unitive benefits of sex.
So instead, whenever they get pregnant they carry the child to term. But instead of raising it themselves, they find a married couple that is looking to adopt and they give the child to them instead. This way the couple in this example only has as many children in their household as they desire, they are respecting the possibility for new life, and they are providing a chance at parenthood to couples who can not have children yet desperately want to.
Is this wrong or sinful?