Screening for birth defects

Today I went in for an ultrasound and blood test to check for the possibility of Down's Syndrome and two Trisonomy disorders (I don't remember the specifics, I missed my nap today). I'm not at high risk, but the test is relatively painless (finger prick) and since my insurance pays for it (and little else) I like having the peace of mind. Of course, this does bring up the question of what would my husband and I do if the tests came back positive. This is something that we discussed before getting married and procreating. Both of us are fervently pro-choice believing that a baby is not a sentient being until it is born and that there is nothing worse than an unwanted child. ( Side note: When I had my miscarriage I had to exam my opinion, for if I believe that birth is what makes a person, then how do I reconcile my feelings of loss and sorry? I had a wonderful discussion with my midwife and was able to come to terms with both without feeling hypocritical.) We feel it isn't fair to bring a child into the world if they are going to suffer beyond the pale for their lives. Nor would it be fair to other children to intentionally have a child that would take all of our time and energy. Not to mention the fact that if such a child were to outlive us then he or she would most likely be a burden upon the state and his or her siblings. I hope that we never have to make such a decision, and weighed with it, I can't guarantee what our decision would be, but I do feel better for both having discussed it beforehand, and having the foresight to take tests that will allow us to make a decision.