May I remind everyone that the same rules that apply to abortion apply to a woman's womb in general? That it could possibly turn into a person someday does not matter anymore than it would in the case of abortion; you do not have a right to tell a woman what she can and cannot do with her body for the sake of the potential eventual personhood of another being. Yeah, it's advisable that a pregnant woman not do things that have a great chance of harming the fetus if she intends to carry it to term, but it's also advisable that people with bad genes not have children because their children are likely to inherit those genes. I know I'd rather my mother have had a drink every now and then while she was pregnant with me than have passed on a long family history of cancer and heart disease. Shall we practice eugenics, for the sake of the children?

We (well, people; I've consciously tried to stop myself from doing it) view women as the guardians of reproduction and children, solely responsible for it all. That's the only reason people are so comfortable telling them what they can and cannot do in regards to reproductive health. There are things men do that affect their sperm and thus their reproductive health, but I've never heard anyone try to tell them they can't do them. So, as was demonstrated by my genes example, it's not really about the potential issues the future children might have, it's about what we're comfortable with, what boundaries of personal rights (such as the right to one's body) we feel are acceptable to violate. We want to control what other people do, especially where reproduction and child-raising are concerned, so any chance we get to do so, we take.