Philosophy professor Andrew Sneddon has given a modified version of the famous “violin” argument for abortion. “I’m going to agree for the sake of argument that the embryo is a human person with the same right to life as all of us. But abortion is justified in the following manner -- imagine this analogy. You are a parent. You have a born child, and you love your child. Your child suddenly gets sick with kidney disease and is going to die unless your child gets a kidney transplant. Imagine that you’re the only person in the world with the right body type so as to be able to donate one of your kidneys and in doing so, save your child’s life. Now, would it be nice of you as a parent to give one of your kidneys to your child? Yes, it would. Would it save your child’s life? Yes. Would it kill you? No, you have two kidneys. But should the law force a parent to give their kidney to their child? No. Just as a parent should not have a legal obligation to give their born child their kidney, the mother has no legal obligation to give her pre-born child her uterus.”
There is one response by a pro-lifer below, and a mighty fine one too, but my take is as follows. Of course, most parents would be willing to donate a kidney to save their child. However, the case against compulsion is, that the donation of a kidney is a permanent thing. The donor will still live, but kidney disease could develop, and then if there is no donation, death; unlike the case of a pregnancy, back up has gone. The uterus is only occupied for nine months, from an act, excluding rape, that involved the active participation of the woman, with the woman if you like, acting in such a way to allow occupation. So, this is quite unlike the kidney example. And, as argued below, the womb has a biological purpose to be occupied by a new human being for the purpose of continuation of the human species. Thus, like most of the arguments by professional philosophers, this one fails as well.