The medical procedure known as preimplantation genetic diagnosis is generally considered by many doctors to be a relatively safe way to work with the genetics of an embryo to help patients avoid some kinds of genetic disorders in a fetus. In preimplantation genetic diagnosis, the embryo undergoes what’s called a blastomere biopsy, where a small piece is taken out of the embryo for evaluation. The end result of this process is a screening of an embryo for certain conditions. The embryos that are found to be most healthy or desirable are used for IVF or in vitro fertilization.
Risks of Preimplantation Genetic Diagnosis
Despite the fact that preimplantation genetic diagnosis has become a popular practice in fertility clinics, some doctors are now saying that there may be a chance for specific risks with this kind of diagnostic method. Animal trials have found some kinds of results that are interesting to scientists who are looking at ways that preimplantation genetic diagnosis may affect fetal and maternal health.
Specifically, according to recent reports, studies are not commonly finding differences in biopsied or “normal” embryos prior to uterine implantation. What some are finding is that there may be a lower rate of successful birth for biopsied embryos. This might just reflect mitigating factors related to the routine processes involved in IVF, but opinions differ on just what this means for the safety of preimplantation genetic diagnosis and embryo biopsy.
Some scientists have also tracked post-birth biopsied embryos in similar animal studies and found some concerning rates of higher body weight as well as levels of neurological function. Some of this research suggests that the developing nervous system could be affected by the process of preimplantation genetic diagnosis, so that some embryos subjected to PGD could be at a higher risk for certain degenerative neurological conditions.
The Preimplantation Genetic Diagnosis Debate
Along with new concerns about health risks of preimplantation genetic diagnosis, some protest the use of this method for ethical reasons. PGD has sometimes been associated with “family balancing” or other terms that some consider euphemisms for control of genetic traits. Although the intent is largely different from primitive birth control processes of past societies, there is still a big debate, illustrated not only in journalistic media, but in science fiction books and movies. This is related to whether preimplantation genetic diagnosis and similar processes will lead to “selection” of desirable birth traits on a societal level, something that some human rights activists argue could be damaging to the community at large.
A general response from the scientific community is that preimplantation genetic diagnosis is largely related to avoiding specific genetic problems that cause grievous birth defects. Monitoring embryos for vulnerability to these conditions can be a way to shield the fetus from harm. All of the research and opinion on preimplantation genetic diagnosis leads to a substantial challenge for families considering how to best plan their births according to their own genetic risks and ancestral makeup.