But our laws aren't based on "moral precepts". They are based on social function.
This line of reasoning is silly. If you are saying that there are laws which prevent the abuses of Dr. Mengele, then so what? That does nothing against my claim that you in principle agree with Dr. Mengele, insofar as both of you draw a strict line between moral precepts and health care practices.
If you are saying that there are laws which prevent the abuses of Dr. Mengele,
and there should be, then you've conceded the point. There are moral precepts which 1. the law should enact and 2. that these laws should govern health care practices.
But note, this only shows that you believe that moral precepts should govern health care practices.
By adding the qualifier "properly" you invite morality into it unnecessarily.
It's not a moral use of the term. There can be a proper function of the organism, medically speaking, even if the exercise is immoral. If I fornicate with a woman and we conceive a child, then her reproductive system is working properly. The act that conceived the child is still wrong.
When I say "properly," I understand that we cannot but conceive of the parts of the organism as teleologically oriented towards some end when we are talking about health. If I say that body part x is healthy, then I recognize that there is a state of affairs which should hold for it, and that if this state of affairs does not hold, then it is not as it should be, that something is wrong with it.
If the heart is working properly, it is beating and pumping blood throughout my body. If it is not doing that, then it's not working properly.
There is a teleology here, but it's not intrinsically a moral one.
Of course they do. The pregnancy they avoid is significantly stressful and endangering to the body's health. You just can't see it that way because you qualify "health" via your own moral imperatives.
The only way that this would work is if you said that pregnancy constitutes a dysfunction of the organism which is pregnant, and that pregnancy is a disease.
As a matter of fact, this is false. One of the bodily system terminates in pregnancy as its teleological end. If a woman is pregnant, it is because various body parts are working properly.