I think your arguments and points you presented have answered all questions I would possibly ask. But do you know that the mother’s amd foetus’ blood do not mix at any point and this is majorly to prevent an immune response. The foetus is not considered self by the immune system technically, the trophoblast just does a good job of keeping it incognito. Antibodies do not particularly cross the feto-placental unit but immunoglobulin G does so and it really doesn’t pose a threat to the foetus anyway.

Good job man !