Tom Harkin: “he pointed out in this letter that sometimes in actual clinical practice even poor quality embryos that might be…”

“he pointed out in this letter that sometimes in actual clinical practice even poor quality embryos that might be considered naturally dead can, by in vitro fertilization, give rise to successful pregnancies. He says he also ``cannot envision an ethically acceptable clinical study that would correlate the pregnancy outcomes of enough poor quality embryos to ensure the reliability of criteria for `embryo death.''' He is saying that the quality for in vitro may be different for in utero. Therefore, it might be a poor quality in vitro, but that doesn't necessarily mean it would be poor quality for implantation in utero. He raises this ethical question. He says: I am skeptical that we can devise any highly reliable criteria to define embryo death that will appease the critics of embryonic stem cell derivation. What you are talking about is the Gardner principle, which has to do with what embryos they implant. That is what that really has to do with. So therefore, sure, you are going to take the healthiest, most vibrant embryo that you are going to implant, first of all, with the hope that it will develop. I still say to my friend that while you can take the ones that don't develop after a week or so and say we will take the stem cells from them--and some happen that way. That is fine. But it just sort of begs the question, if you really want to derive the best stem cells, why wouldn't you use the healthiest embryos rather than the sickest embryos?”