More about these numbers:
The same study from SART and the RAND corporation reported the different uses for frozen embryos (FE):
'patient treatment' was most common (87%)
destruction, over 2.2%
'research', over 2.8%
since research necessarily involves destruction, over 5% of FEs are destroyed.
What happens is that embryos are stored by freezing, and they tend to remain frozen for years. More embryos are being put into freezing than are being thawed and transferred to the womb. So the number of frozen embryos is continually increasing.
The above cited study was done in 2003, and found about 450,000 FEs. By now it is likely that the number has increased to over 500,000, just in the U.S. Worldwide, the number of FEs is quickly approaching one million.
The percentage of destroyed embryos (including research) is said to be 5% (2.2 plus 2.8). But this refers to stored embryos that were scheduled for destruction (or 'research'). The actual number must be higher as a percentage because the stored embryos remain stored, even year after year. But the embryos scheduled to be destroyed soon are gone. So consider ten years of embryo freezing. Most embryos remain frozen, year after year. So at the end of the ten years, say 87% are kept for possible patient treatment, but there is no treatment scheduled for most. But the 5% that are scheduled for destruction have not been waiting for destruction for ten years. They are destroyed relatively soon.
Embryos destroyed in past years are not included in the 5%. But many embryos frozen in past years are included in the 87% because they remain in storage. Therefore, the estimate of 5% is lower than actual.
Roman Catholic theologian