On June 14, Swiss voters approved pre-implantation genetic diagnosis for testing human embryos created through in vitro fertilization (IVF). The tests, which are common in some US states and banned entirely in some countries, screen for genetic defects and diseases before the embryos are implanted into a mother’s womb.

Also recently, the Ministry of Parliament in the UK passed a law allowing three-parent babies using DNA from two women and one man to avoid passing down diseases tied to a mother’s mitochondria. And a new gene-editing technology called CRISPR/Cas9 has now been applied to humans, meaning that researchers can now remove faulty sections of the genetic code and swap in beneficial ones.

But, in the future of reproduction and health, where does therapy stop and vanity start, and who draws that line?

There are worldwide concerns that recent advances are steps on a slippery slope toward designer babies and DNA editing that alters heredity forever, possibly changing human evolution. But how justified are these concerns really? And how can society balance scientific breakthroughs with differing beliefs about what’s ethical?

Fertility and Designer Babies

Getting pregnant naturally has become more difficult as people in many societies opt to delay parenthood until later in life. This is why, once a scientific novelty, IVF has become routine today in many countries.

According to the US Department of Health And Human Services around 12 percent of women of childbearing age have received assistance for infertility. Pre-implantation genetic diagnosis (PGD) comes into play to screen these embryos for genetic disorders, as explained by the American Pregnancy Association.

But the use of PGD can be extended to other traits. Parents can theoretically choose the sex or even eye color of their baby. The founder of The Fertility Institute in Los Angeles and New York, Dr. Jeffrey Steinberg, who carried out his initial training at Bourne Hall Clinic at Cambridge University in England (the birthplace of IVF), not only offers the service of selecting a baby’s sex but also ensuring a healthy genotype. And lately he has had customers choose the eye color of their child.

The idea of selecting for some ideal of perfection isn’t new. Genetic testing and engineering is just making it more precise.

An early pioneer in the field of “designer babies” was Robert Grayham, whose so-called genius sperm bank accepted only donors who were scientists, prodigies, or athletes with an IQ of at least 130.

US singer Leandra Ramm, who lives in the suburbs of San Francisco, is one of the first designer babies.

Three-Parent Babies and Germline Engineering

In February 2015 in Britain, the Members of Parliament said yes to a law that allows doctors to use the DNA of a second mother to fix the genetic code of babies at risk of mitochondrial disease, which occurs when the mitochondria—the tiny powerhouse organelle inside cells—fails to function properly.

There are no treatments for mitochondrial disease, so women who have them are likely to pass them on to their children.

Here’s how the three-parent technique works: If the mitochondrial genes of the mother contain known errors that lead to disease, then the entire nucleus (containing 46 chromosomes) of a fertilized egg are removed and placed into the nucleus of a fertilized donor egg that has had its DNA taken out.

In this way, the resulting IVF embryo contains the chromosomes of the mother and father from the nucleus but the healthy mitochondrial DNA of the donor, or second mother.

While critics scorn the practice, which involves creating and then destroying a fertilized egg, Britain has become the only countries in the world where this procedure is legal. US regulators, meanwhile, have adopted a go-slow approach, according to Scientific American.

And then there’s CRISPR/Cas9. Using this technique, scientists change DNA sequences to correct genetic defects in animals and cultured tissues from stem cells, potentially yielding powerful new methods for treating human disease.

But there are serious concerns about the use of CRISPR on germline (sperm and egg) cells that can be passed on to future generations, as little is known about any unintended consequences of the practice.

Nevertheless, in April 2015 a Chinese team at Sun Yat-sen University in Guangzhou published in Protein& Cell that it has altered the genetics of a human embryo for the first time ever with this technology.

Dr. Perry from the University of Bath, UK, said in an interview with the BBC News website in January that editing the DNA is a wonderful opportunity to remove horrible diseases and that it would be unethical not to explore it.

“I think it is a sin of omission, if you have a method where you can prevent someone suffering and you don’t take that opportunity then it is wrong, it is unethical,” Perry stated, and called on government and research bodies to fund more research in this field.

But Marcy Darnovsky from the US Center for Genetics and Society criticized the use of the CRISPR/Cas9 method by saying, “The medical risks and social dangers of human germline modification cannot be overstated. Creating genetically modified human beings could easily lead to new forms of inequality, discrimination and societal conflict.”

According to UC Berkeley, a group of 18 scientists and ethicists that included co-inventor of CRISPR-Cas9, Jennifer Doudna, published a perspective piece in the March 20 issue of Science urging caution and strongly discouraging making changes to the human genome that could be passed on.

“Given the speed with which the genome engineering field is evolving, our group concluded that there is an urgent need for open discussion of the merits and risks of human genome modification by a broad cohort of scientists, clinicians, social scientists, the general public and relevant public entities and interest groups,” the group wrote.


Whether the powerful new tools and techniques for genetic screening and alteration become widespread today or tomorrow, there surely appears to be a tendency toward weeding out disease and building healthier humans.

But will this march stop at disease-free babies, or extend toward selection of special abilities, extraordinary intelligence, or even beauty? It’s hard to imagine the outcome now, but the debate will surely live on—perhaps in future generations, coded in our genes.

Featured image by Fanny Vaucher from the Centre de formation professionnelle pour les arts appliqués (CFPAA) in Geneva, Switzerland. The illustration was made for the exhibition Made in Utero, La naissance de la vie and for the book project Zooïne, sur les sentiers de la vie, by Vivienne Baillie Gerritsen.