Japanese researchers announced last year that healthy, fertile mice had been born using eggs created from cells in the tail tips of male mice. Eggs of male origin were fertilized with normal sperm, thus producing pups with two fathers. Reproductive biologist Katsuhiko Hayashi, who led the work at Kyushu University, believes it will be technically possible to create a viable human egg from a male skin cell within a decade, according to The Guardian.
This finding builds on previous work in which another team of Japanese researchers created mouse eggs from tail tip cells that led to the birth of healthy offspring in 2017. Another Japanese research team in 2021, using stem cells mouse, created sperm that produced healthy, fertile offspring.
Now researchers at private biotech companies like Conception Bio and Gameto are racing to see if they can develop this in vitro gametogenesis (IVG) technology as a way to safely enable post-menopausal women, couples suffering from infertility and same-sex couples to bear biologically related children. Perhaps even solo reproduction where single men could produce both sperm and eggs which combined would lead to them having biological children in the future.
Keep in mind that only seven healthy mouse pups were born from the 630 embryos from two fathers transferred by Japanese researchers. Therefore, major technical hurdles must be addressed before IVG can be safely used to give birth to human babies. But some people resist pursuing human procreation using IVG even after it becomes as safe as conventional and in vitro fertilization (IVF) births.
IVG is “a perversion of the sacredness of procreation as a fundamental aspect of human life,” said Ben Hurlbut, a bioethicist at Arizona State University, in United States today. He added: “It becomes an industrial project that responds, inspires and cultivates the desires of future customers.” Marcy Darnovsky, head of the left-leaning Center for Genetics and Society, warned on NPR that IVG “could lead us into some kind of Gattaca world.” (He was referring to the 1997 science fiction film in which a eugenicist state is ruled by people born with genetically enhanced abilities.) Federalist, Jordan Boyd states that by developing IVG, “the global fertility industry seeks to eliminate women from procreation, one egg produced at a time.”
The National Academy of Sciences addresses many of these ethical concerns in its Report on the Conference Proceedings on In Vitro-Derived Human Gametes published in October 2023. That report summarizes the findings of a conference on the topic convened by the NAS in April 2023 .
Far from “wiping out women,” IVG will instead allow otherwise infertile women to produce as many eggs as they want without having to undergo treatments such as ovarian stimulation in the hopes of producing enough eggs to succeed with conventional IVF.
Hurlbut is right that many people consider procreation to be a “fundamental aspect of human life.” This would be especially true for the 9% of men and 11% of women of reproductive age in the United States who have experienced fertility problems. Then there are people who are past the conventional reproductive age and same-sex couples who would like to have biologically related children. Far from being an “industrial project”, the introduction of safe IVGs would satisfy the desire of these future customers to build their own families.
What to say Gattaca fears? The report recognizes that “combining IVG with polygenic risk screening could revolutionize the ability to select embryos.” Polygenic risk screening (PRS) picks up genetic variants that increase each embryo’s chances of developing a particular disease or trait. This is similar to the already widely accepted practice of preimplantation genetic diagnosis during in vitro fertilization, in which parents test and select embryos to avoid deleterious hereditary conditions. PRS would increase the ability of prospective parents to select their preferred combination of traits among many more embryos.
Rather than limit the use of PRS, Hank Greely, a bioethicist at Stanford University, suggested that “in general, it is better to rely on parental choices to make decisions about how people want to create families.” This comes from the reasonable assumption that parents generally seek to provide the best life for their potential offspring. The sad history of eugenics laws in the United States, where tens of thousands of people were forcibly sterilized during the 20th century, should make anyone wary of government interference in people’s reproductive choices, including the use of Safe IVGs. As law professor Michele Goodwin of the University of California, Irvine has rightly observed, “Where the law has intervened over time in matters of reproduction, it has served to undermine civil liberties and civil rights.”