The idea of selecting or engineering traits in human offspring is older than most people realize, stretching back decades before modern gene-editing tools existed. The term “designer baby” entered public conversation in the late 1970s alongside the birth of the first test-tube baby, but the impulse to shape human heredity has roots in early 20th-century eugenics movements. What changed over time was not the desire but the technology, moving from crude selective breeding ideas to precise molecular tools capable of rewriting individual genes in a human embryo.
The Birth of IVF and Early Fears
On July 25, 1978, Louise Brown was born in England, the world’s first baby conceived through in vitro fertilization. The reaction was not entirely celebratory. Princeton theologian Paul Ramsey called it “one step along toward further modes of manufacturing our children.” British members of Parliament warned of “scientific breeding” and invoked Adolf Hitler’s concept of a master race. American news anchors quoted doctors who feared “a nightmare of biological engineering.” Much of the anxiety drew from Aldous Huxley’s 1932 novel Brave New World, in which humans were gestated in bottles and sorted into social castes before birth.
These fears were speculative in 1978. IVF simply allowed fertilization to happen outside the body, with no selection of traits involved. But the technology created a crucial precondition: once embryos existed in a lab dish, it became possible to examine them before implanting them in the uterus. That possibility would become reality within a dozen years.
The Nobel Prize Sperm Bank
Before genetic screening existed, one entrepreneur tried a low-tech approach to designer babies. In 1980, California millionaire Robert K. Graham opened the Repository for Germinal Choice, quickly nicknamed the “Nobel Prize sperm bank.” Graham initially recruited three Nobel laureates as donors, including transistor inventor and controversial race theorist William Shockley. He later shifted to younger donors from the campuses of UC Berkeley and Caltech, prioritizing intelligence and physical fitness.
The repository arranged for 229 children to be born before it closed in 1999, shortly after Graham’s death at age 90. The project was widely criticized as a revival of eugenic thinking, and follow-up reporting found that the children turned out to be a normal range of people. But the repository illustrated a persistent cultural fascination with engineering “better” offspring, even through something as simple as choosing a sperm donor.
Preimplantation Genetic Diagnosis Arrives
The first real tool for selecting embryos based on their genetics arrived in 1990. That year, researchers reported the first successful use of preimplantation genetic diagnosis, or PGD. The technique worked by removing a single cell from an embryo created through IVF, analyzing its DNA, and transferring only embryos that did not carry a targeted genetic condition. In this first case, the goal was to avoid an X-linked disorder by identifying and selecting female embryos for transfer.
PGD expanded rapidly through the 1990s and 2000s. Clinics began offering screening for conditions like cystic fibrosis, sickle cell disease, and Huntington’s disease. The technology also made sex selection possible for non-medical reasons, which some clinics, particularly in the United States, offered to paying clients. This blurred the line between preventing serious disease and choosing traits, reigniting the designer baby debate in concrete rather than hypothetical terms.
Three-Parent Babies and Mitochondrial Replacement
A separate line of reproductive technology pushed into new territory: mitochondrial replacement therapy, sometimes called “three-parent IVF.” Mitochondria are tiny energy-producing structures inside cells, and they carry their own small set of DNA inherited exclusively from the mother. When a mother carries mutations in her mitochondrial DNA, the results can include severe muscle weakness, organ failure, and early death in her children.
Mitochondrial replacement works by transferring the nucleus of the mother’s egg into a donor egg that has healthy mitochondria, then fertilizing it. The resulting child carries nuclear DNA from both parents and a small amount of mitochondrial DNA from the donor. The United Kingdom approved the technique in 2015, making it the first country to legalize a form of heritable genetic modification in humans. A team working in Mexico also reported a successful birth using the technique for a mother who was a carrier of a serious mitochondrial mutation. The baby was reported healthy at 11 months.
CRISPR Changes Everything
In 2012, Jennifer Doudna and Emmanuelle Charpentier published the work that would earn them the Nobel Prize: a method for using a bacterial defense system called CRISPR-Cas9 as a precise, programmable gene-editing tool. Unlike PGD, which can only select among existing embryos, CRISPR could theoretically rewrite specific genes in an embryo, correcting mutations or even introducing new traits.
The leap from theory to practice was fast. In April 2015, a team from Sun Yat-sen University in Guangzhou, China, published the first report of CRISPR being used on human embryos. The embryos were non-viable (they could never have developed into babies), and the results were mixed, with many unintended edits. Both Nature and Science had rejected the paper before it was published in a smaller journal, reflecting the scientific community’s deep discomfort with the work. Still, the line had been crossed.
That same year, the First International Summit on Human Genome Editing convened in Washington, D.C. Scientists from around the world agreed that basic research on editing human embryos could proceed, but that it would be “irresponsible” to use edited embryos to establish a pregnancy until safety and ethical issues were resolved.
The CRISPR Baby Scandal of 2018
The international consensus held for exactly three years. In November 2018, Chinese biophysicist He Jiankui announced that twin girls, known by the pseudonyms Lulu and Nana, had been born with genes edited using CRISPR. He claimed to have disabled a gene called CCR5, which produces a protein that HIV uses to enter cells, in an attempt to make the children immune to the virus.
The scientific community reacted with near-universal condemnation, and for reasons that went beyond ethics. Analysis of He’s own data revealed that neither twin actually carried the specific 32-base-pair deletion in CCR5 that confers natural HIV resistance. Instead, each embryo had different, unpredictable mutations of various lengths, with unknown consequences. The CCR5 gene is also involved in brain function, meaning He may have inadvertently altered the children’s cognitive development in ways no one can predict.
He Jiankui’s experiment violated Chinese regulations that, while not highly detailed, provided no legal basis for implanting edited embryos. He was sentenced to three years in prison and fined roughly $430,000. The Second International Summit on Human Genome Editing, which happened to be taking place in Hong Kong the same week He made his announcement, issued a statement calling the experiment “deeply disturbing” and “irresponsible.”
Where Global Regulation Stands
A 2020 survey of 96 countries found a patchwork of rules. Eleven countries, including China, India, the United Kingdom, Japan, Thailand, and the United States, allow laboratory experiments on human embryos involving germline editing under various restrictions. In the U.S., this work can only be funded with private or non-federal public money, since Congress has blocked federal funding for research that creates or destroys human embryos. Nineteen countries explicitly ban even experimental germline editing. Fifty-six countries have no clear policy at all.
No country currently permits heritable genome editing, meaning no government allows edited embryos to be implanted for pregnancy. Seventy countries have explicit policies against it. In 2021, the World Health Organization published a governance framework and set of recommendations for human genome editing, developed by an expert advisory committee. The framework called for a global registry of all genome editing research and emphasized that any move toward clinical use would require rigorous oversight, legal authorization, and demonstrated safety.
The Third International Summit, held in 2023, reaffirmed that heritable human genome editing should not proceed until it meets “reasonable standards for safety and efficacy, is legally sanctioned, and has been developed and tested under a system of rigorous oversight.” The organizers noted that, as of 2023, those conditions had not been met. The summit also broadened its focus to include somatic gene editing (changes to non-reproductive cells that cannot be inherited), which is already being used in approved medical treatments for conditions like sickle cell disease.
The Line Between Treatment and Enhancement
Much of the designer baby debate comes down to where you draw a single line: the difference between preventing disease and enhancing traits. Few people object to screening embryos for fatal genetic conditions. More object to selecting embryos based on sex. And the prospect of editing genes to increase intelligence, height, or athletic ability provokes the deepest resistance, in part because these traits are influenced by hundreds or thousands of genes interacting with environment in ways scientists do not yet understand.
The history of designer babies is, in many ways, a history of technology outpacing the ethical frameworks meant to govern it. IVF arrived before anyone had agreed on rules for embryo research. PGD was used for sex selection before regulators decided whether that was acceptable. CRISPR was applied to human embryos before the first international summit could finish drafting guidelines. Each leap forward has forced societies to answer the same question that worried commentators in 1978: how much control over our children’s biology is too much? The tools keep changing. The question has not.