likely danger to the implanted fetus or the eventual newborn if reproductive cloning of humans is attempted in the near future are compelling.
The panel has based its support for the proposed ban on human reproductive cloning on the following findings:
Finding 1: The scientific and medical criteria used to evaluate the safety of reproductive cloning must be the potential morbidity and death of the woman carrying the clone as a fetus and of the newborn and the risk to women donating the eggs.
Finding 2: Data on the reproductive cloning of animals through the use of nuclear transplantation technology demonstrate that only a small percentage of attempts are successful; that many of the clones die during gestation, even in late stages; that newborn clones are often abnormal or die; and that the procedures may carry serious risks for the mother. In addition, because of the large number of eggs needed for such experiments, many more women would be exposed to the risks inherent in egg donation for a single cloning attempt than for the reproduction of a child by the presently used in vitro fertilization (IVF) techniques. These medical and scientific findings lead us to conclude that the procedures are now unsafe for humans.
Finding 3: At least three criteria would have to be fulfilled before the safety of human reproductive cloning could be established:
The procedures for animal reproductive cloning would have to be improved to such an extent that the levels of observed abnormalities in cloned animals, including nonhuman primates, were no more than that seen with existing human assisted reproductive technology (ART) procedures. If that could not be achieved, researchers would have to demonstrate that humans are different from other animals with regard to cloning-related defects. Reproducible data demonstrating that a successful reprogramming of the donor nucleus and proper imprinting can be achieved in animals would be essential, as would an understanding of the mechanisms responsible for such events.
New methods would have to be developed to demonstrate that the human preimplantation embryos produced through the use of nuclear transplantation technology are normal with respect to imprinting and reprogramming. That would best be done by first establishing the normal state of reprogramming and imprinting in nonhuman primates and then documenting that the processes in preimplantation human embryos are substantially similar.
Methods would have to be developed to monitor—effectively