MORE than 1m embryos created for fertility treatment in British clinics have been destroyed over the past 14 years, government figures have shown.
The Department of Health data show that 2,137,924 embryos were created using IVF between 1991 and 2005, but about 1.2m were never used.
While political opposition to the creation of embryos to extract embryonic stem cells remains strong the rate of destruction of embryos is already high without the use of embryos for this purpose. More embryos get created than used for a few reasons. First off, women trying to start a pregnancy using IVF get extra embryos created because they don't know how many attempts will be needed or even how many fertilizations will succeed in creating viable embryos.
Also, the development of tests (genetic and otherwise) for checking on the health of embryos leads to the identification of unhealthy embryos before implantation. These tests are becoming more powerful and as a result many embryos can be judged to either be unlikely to start a pregnancy or to result in birth defects.
The development of increasingly more powerful genetic tests for pre-implantation genetic diagnosis (PIGD or PGD) of embryos will lead prospective parents to become much more selective in choosing embryos. As the significance of more genetic variations becomes known people will have far more reasons to choose between different embryos. The trend is going to be toward the creation of far larger numbers of embryos so as to increase the odds of finding an embryo will be found that contains the best combination of genes from the two parents. Basically, people will throw the genetic dice more times in order to better their odds.
The era of large scale excess embryo creation will last a few decades at most. That era will end with the development of nanotechnological tools that will provide the means to select each chromosome to put in an egg, sperm, or embryo. Rather than throw the dice many times we'll gain the ability to basically put down the genetic dice with the combination we desire.
|Share |||Randall Parker, 2007 December 29 10:53 PM Bioethics Reproduction|