Image from Nature Reviews Genetics 3, 941-955 (December 2002)

While this technology offers the hope to increase the success of IVF, it does raise some concerns about choosing a child in order to meet the needs and desires of parents. While most cases seem to have parents that are trying to increase their chances of having a viable pregnancy, some have raised some major ethical dilemmas. For example, two parents with achondroplasia, a disorder of bone growth that causes the most common form of dwarfism , is caused by having only one mutated copy of a gene. These parents might want to avoid an embryo that receives a mutated copy from both parents, which would be lethal. Instead, would they possibly choose an embryo that only has one affected copy, which would result in a child with achondroplasia, instead of an unaffected embryo? Would an unaffected child suffer more in an achondroplastic family than an affected child in such an environment?

This technique can be applied in a variety of ways, but I wonder if there are more ethical concerns than anything else. With any new technology, just because we can, should we? Are parents going to do this just to have a child free of genetic disease? Or is the future of “designer babies” closer than we think?

These definitions stress differences that occupied either end of a continuum of eugenics practice. At one end, Galton’s definition stressed social control, or laws, to control human reproduction. At the other end, Charles Davenport’s stressed an individual’s own control over their reproduction. Social control ultimately embodied “negative eugenics”– limiting mixed race marriages, restricting immigration from southern and eastern Europe, and sterilizing mental and epileptic patients. Self-direction embodied “positive eugenics” – taking personal measures to improve one’s own genetic heritage through mate selection.

Of course, things weren’t that simple. Galton never strongly advocated for negative eugenics, and England never inacted coercive eugenics legislation. To the contrary, Davenport’s Eugenics Record Office successfully lobbied state governments and the U.S. congress to enact restrictive eugenics legislation that culminated in the U.S. Supreme Court upholding the premise of compulsory sterilization.

The Holocaust represented the nadir of eugenic practice, but it would be wrong to think eugenics ended with the Nazis. As examples, ethnic cleansings continue to this day in Darfur, and disincentives against large families trump personal reproductive wishes in China. At the same time, fertility drugs and in vitro fertilization extend reproduction to infertile couples, and pre-implantation DNA diagnosis puts the ultimate slant on the notion of self-directing of human evolution.

And somewhere in between is the simple act of picking the healthiest, most virile mate we can find to help us propel our genes into the future. We all lie somewhere on the continuum of eugenics practice.