I think a lot of folks have clones and even abortion in the back of their minds when it comes to Stem Cell research. Of course things get even hairier to consider when you think about the IVF process and what unneeded embryos mean to a couple. First and foremost, IVF is expensive. Most insurance companies won't pay for it, and therefore, couples try to create as many eggs (and as a result hopefully embryos) as they possibly can in one cycle so they have the best chance of success having a baby.
Many of them have no leftover embryos to cryogenically freeze for another try, but some couples get a plethora of extra embryos, which are frozen just in case the fresh cycle is unsuccessful. The reason they freeze them is that the original cycle is very physically and emotionally trying and the meds used are expensive.
When the family is complete, there is suddenly a big problem: What do you do with extra embryos. Some folks adopt them out (snowflakes), but a lot of people leave these embryos in storage because they don't exactly want to destroy them, but they also don't feel comfortable with someone else giving birth to their biological child.
Basically at the point they are frozen, these embryos look like a cluster of grapes and do not know what they are to yet become. They can be programmed to be any type of body cell, including nerve cells, which supposedly can never repair on their own.
There is also a process by which a single cell can be harvested from one of these embryos, and there is also a lot of talk about umbillical cord stem cell harvesting, but the potential for these two technologies is lost on the anti-stem cell research sentiment. And, by the way, couples do have a single cell removed from a blast embryo quite often prior to implantation so that the embryo can be tested for genetic problems.
