The slogan, “Have your best baby,” running across the homepage of Nucleus Genomics, captures a new chapter in reproductive technology: using DNA to predict and select the next generation.

As embryo genome screening companies promise parents more control over their children’s genetic traits, the line between detection and perfection begins to blur.

Biotech companies like Nucleus Genomics and Orchid are marketing new tools that let parents analyze embryo genomes during In Vitro Fertilization. These services detect monogenic disorders such as cystic fibrosis,  as well as predict predispositions for complex conditions like breast cancer and diabetes using Polygenic Risk Scores.

Now, the same technology is being promoted as a way to go beyond disease detection by allowing parents to select embryos for non-medical traits like height, eye color, or even intelligence.

But what does it mean to pick the “best” baby, and should we even try?

According to Jan Liphardt, scientific advisor for genetic selection company Orchid and associate professor of Bioengineering at Stanford, Orchid’s technology can sequence the entire genome of an embryo, allowing parents to detect risks for serious health conditions.

“Not only is Orchid able to look at individual genes, but, by virtue of its amplification technique, Orchid is able to get whole genome sequence data for the entire genome of specific embryos,” Liphardt said. “The information you get out of that [PRS] is not a simple yes or no answer; it’s risk — for example, our risk of developing diabetes in 70 years from now.”

According to Hank Greely, director of the Center for Law and the Biosciences at Stanford, genes influence multiple traits at once, which can lead to significant trade-offs when selecting an embryo.

“Most allele variations in genes do more than one thing, and sometimes they do a good thing, and sometimes they do a bad thing at the same time,” Greely said. “If you pick a particular embryo based on a Probability Risk Score for high IQ, maybe it also has a high risk of schizophrenia or a high risk of early onset cancer.”

Greely said PRS is not as predictive as it’s marketed to be, especially for traits like high intelligence.

“PRS is not universally believed in by geneticists — I think there are a lot of geneticists who think it is, but it needs to be proven better,” Greely said. “The most optimistic people involved in PRS for intelligence will say, ‘We could make a three or four IQ point difference.’ Well, a three or four IQ point difference is less than the difference you get if you take the IQ test two days in a row.”

For many families, however, PRS embryo selection is just good parenting.

Janet Malek, a clinical ethicist and professor of Medical Ethics and Health Policy at Baylor College of Medicine, said parents’ desire to select the “best” embryo is an extension of common efforts to maximize their children’s opportunities.

“There is something very reasonable about parents wanting to do what’s best for their kids,” Malek said. “Why is it okay to get them tutors, to take them around and make sure they have opportunities to play sports and play music, but it’s not okay to choose their genes in a particular way?”

According to a Wall Street Journal article titled “Inside Silicon Valley’s Growing Obsession With Having Smarter Babies,” written by Zusha Elinson, Palo Alto may be especially receptive to this kind of thinking.

“The fascination with what some call ‘genetic optimization’ reflects deeper Silicon Valley beliefs about merit and success,” Elinson said.

Greely said he attributes much of this enthusiasm to the region’s faith in genetics and technology.

“It [embryo genome selection] is a product of a combination of an overly strong belief in genetic determinism, and in a population that is especially predisposed to think that technology is always going to work,” Greely said. “They [buyers] are rich people who want the very best for their kids and are technophiles.”

Palo Alto High School senior Amalia Tormala, president of Paly’s Black Student Union, said that because of its hefty price tag, genetic optimization technologies risk only benefiting the wealthy and exacerbating economic inequalities.

“As it gains popularity and becomes slightly more mainstream, genetic optimization will likely primarily be available to the wealthy, which very well may further the socioeconomic disparities that are already incredibly present in an area like Palo Alto,” Tormala said.

Tormala also said she saw similarities between these new technologies and previous genetic optimization movements.

“I find it somewhat off-putting,” Tormala said. “To me, it mirrors a lot of the 19th and early-20th-century eugenicist ideologies that were so present in Palo Alto.”

According to Murphy Haliburton, professor of Anthropology at Queens College and Gunn High School alum, eugenics is the effort to intervene in human heredity to improve the human population. Haliburton said while he acknowledges the ideological parallels, embryo genome sequencing is distinct because it is individualized.

“If people are trying to find a gene for intelligence, well, that’s what eugenicists did,” Haliburton said. “These things look like eugenics, but it will probably be done on an individual consumer sort of basis rather than a state-level force policy. So maybe we can give it a new name.”

Paly alum Kobi Johnsson said selecting for traits crosses a line.

“I think that gets to a level of playing God … assuming that you have the total ability to take control of somebody else, even if they are your child,“ Johnsson said.

Greely said embryo screening companies operate in an emerging industry with few safeguards to ensure safety or effectiveness.

“It is deeply unethical to sell something that doesn’t work, that you know doesn’t work, by misleading people into thinking it works, or by being overly optimistic and not being skeptical enough,” Greely said. “Orchid doesn’t have to prove to anybody that their test works or that it’s safe, and I think that’s a mistake.”

Despite these ethical dilemmas, Greely said he predicts that IVF and embryo selection will become the default method for reproduction, first for health reasons, then for enhancement.

“We will get there, in 30 to 40 years, but we will get there not because of an enhancement, but because of a desire for healthy kids,” Greely said. “If IVF and hence Preimplantation Genetic Testing were cheap, easy and comfortable, I think a lot of parents would do it just to avoid that 1 or 2% chance [of an embryo with a serious monogenic disease], and along the way, they would also maybe get to select embryos that would have dark eyes or straight noses or curly hair.”