There was immediate backlash when Alabama’s Supreme Court ruled in February that embryos created through in vitro fertilization qualified as children under the state’s wrongful death law. But it was a backlash as much from the right as from the left: The state’s overwhelmingly Republican government took just weeks to pass a law to shield fertility clinics from liability when embryos are damaged or destroyed.

It seemed the fight over I.V.F., as a cultural question, was over before it began. In May, 82 percent of Americans polled by Gallup said they believed I.V.F. is morally acceptable. In response to public pressure, Donald Trump recently promised to defend I.V.F. with federal protections and even a theoretical mandate that health insurance pay for it.

This wasn’t inevitable. A generation ago, bioethicists fought over whether assisted reproductive technology would be normalized or made taboo. Now there’s strong public consensus that it should be not only tolerated but also celebrated.

But this may be a lull. With major technological advances in childbearing on the horizon, what was once hypothetical is becoming plausible, setting the stage for a potentially tumultuous shift in the cultural mood about assisted reproduction.

Consider in vitro gametogenesis, or I.V.G., a technology under development that would allow the creation of eggs or sperm from ordinary body tissue, like skin cells. Men could become genetic mothers, women could be fathers, and people could be the offspring of one, three, four or any number of parents.

The first baby born via I.V.G. is most likely still a ways off — one researcher predicts it will be five to 10 years until the first fertilization attempt, although timelines for new biotech are often optimistic. But the bioethicist Henry Greely, noting the benefits of allowing same-sex couples to have genetic offspring and I.V.F. parents to pick the most genetically desirable of dozens or even hundreds of embryos, predicts that eventually a vast majority of pregnancies in the United States may arise from this kind of technology. Debora L. Spar, writing about I.V.G. for Times Opinion in 2020, echoes the view that such advances seem inevitable: “We fret about designer babies or the possibility of some madman hatching Frankenstein in his backyard. Then we discover that it’s just the nice couple next door.”

But once a technology like I.V.G. enters the public view, will the sentiment about reproductive technologies stay settled? After all, Americans sometimes make surprising turns against technologies they once embraced, and we are in the mood for backlash today. Americans are disenchanted with smartphones for kids, social media, nuclear power and processed food, and their former faith in technology to solve the oldest human frustrations has recently frayed. A turning against reproductive technology could be next — not least because Silicon Valley, the focal point of much of today’s criticism, is getting more involved.

Classical-liberal critics of assisted reproductive technology, among whom I count myself, argue that it can unethically turn the arrival of a child, which should be considered a gift, into a project. We undertake projects to realize our own ambitions. We exert control, select useful material to meet desired outcomes and throw out waste.

The irony of the science fiction story “Gattaca” is that the most oppressed character was not the one at a biological disadvantage but the one whose parents’ designs for him were forever written into his biology. His life was not fully his own.

It’s remarkable that this idea is so omnipresent in our culture and yet has little to no purchase in how we think about today’s reproductive technologies. Preimplantation genetic diagnosis is a procedure that analyzes I.V.F. embryos and lets technicians discard those with genetic abnormalities, like Down syndrome, or pick those with a desired trait, like male over female. Sex-selective abortion, widely practiced in India and China, is already making real a genetic overclass (boys) and a discardable underclass (girls). Then there is what my colleague Brendan Foht calls “kinship engineering” — egg and sperm donation, surrogacy and mitochondrial replacement therapy, which are billed as fertility treatments or as medical therapies but actually ensure desired kinship relationships.

Though these practices satisfy the preferences of parents, the fertility industry frames its services in the language of gift giving, particularly egg donation and surrogacy — both to the women supplying the eggs and the parents seeking them. The technologies we already have for selecting children’s traits are likewise broadly seen in our culture as ways of providing children with the gift of the best possible life.

But what happens when the figures most associated in the public mind with pushing for reproductive technologies switch from the nice couple next door to Silicon Valley tech overlords?

Consider the recent attention to Elon Musk’s pronatalist ambitions, especially his desire for “smart people” to have more children, his reported extensive use of I.V.F. and surrogacy and his serving as a sperm donor to live up to his word. Even amid a discourse overwhelmingly committed to liberalization of reproductive technology, it is striking how willing commentators have been to recognize something here that is just … well, weird.

It could be a portent. The Information recently reported on how billionaires like Sam Altman, Peter Thiel and Brian Armstrong are “behind a boom in fertility tech start-ups developing sophisticated embryonic testing, sperm freezing — even artificial wombs.” The subtext is unmistakable: Just imagine the headlines if the first baby born from an artificial womb is not to a sympathetic middle-class couple unable to conceive after a hysterectomy but to a polycule of tech gurus with designs of populating a seasteading colony.

Or imagine that a public already steeped in angst about emerging technology simply responds to I.V.G. and its prospect of making children from a man’s egg or a woman’s sperm not as a warm extension of the human experience but as a radical break from it, a project too far. The public reacted this way before in overwhelmingly rejecting cloning.

If we find these scenarios plausible, even just as thought experiments, it tells us that the prophets of inevitability are wrong and that the public mood toward assisted reproduction could still turn sour. But we shouldn’t wait for the messiness of a tech backlash. Instead, we must let ourselves see the little ways that we are already living in the world sci-fi writers imagined — a world where we persuade ourselves that designing children to match our dreams is something we do for them rather than for us — and begin setting limits now.