That's right, or rather its the mother that gives the fetus the right. Think of it like this, you mentioned that in your house your children (as long as they are underage) have no right to privacy. You say you are allowed to take their doors off the hinges, search their rooms etc. Well whatever privacy you allow them is something you have given them as you established those under your roof. You say they do not have the right to medical privacy because you pay their bills and make their appointments, even if its their body, right? Well you do this because they are YOUR charge and this is true even if they can walk and talk and express themselves. A fetus is a growth in a woman's body and as long as its in her body its her charge, so just like you give your kids the rights you decide they should have so the mother does with her unborn.