bodily autonomy?

Don't circumcision and ear piercing go against the bodily autonomy law? It's always confused me that someone can't take your blood to save someone that's dying if you don't want them to, but a parent can circ/pierce their baby. Someone explain please? Pls don't post your opinion about circ/ear piercing in the comments. This isn't a debate, I'm just confused about what I asked that's all I want an answer to please