Alzheimer, cancer, SMA, and Parkinson's diseases. Some stem cell research is done by using human embryos, and one option that parents have once they are done with in vitro fertilization is to donate their unused embryos to stem cell research. One review came to the result that the proportion of IVF users who donated embryos for research varied geographically, from 7% in France to 73% in Switzerland. A study done in the United States revealed that 60% of American donors would donate the unused embryos to science. People who donate embryos for research often have been found in a review to report feelings of reciprocity towards science and medicine, positive views of research and high levels of trust in the medical system. They have described the decision to donate as better than the destruction of embryos, and as an opportunity to help others or to improve health and IVF technology. On the other hand, reported factors that make people refrain from embryo donation to research include a perception of risks, a lack of information concerning research projects and the medical system, as well as conceptualization of embryos in terms of personhood. The influence of sociodemographic characteristics and reproductive and gynecological history have mainly been found to be inconclusive. See also Assisted reproductive technology Snowflake children Snowflakes® Embryo Adoption & Donation References External links Preborn Babies National Registry for Adoption National Embryo Donation Center Embryo Adoption & Embryo Donation Academy Fertility medicine Giving