A U.S. fertility doctor has started a company with a provocative vision for older women: become pregnant by having their DNA shifted into a young woman’s egg.
The company, Darwin Life, was quietly established last year by John Zhang, also founder of a New York City clinic called New Hope Fertility Center, to deploy a cutting-edge fertility technology called “spindle nuclear transfer.”
It was originally developed as a way to prevent women from passing certain rare diseases on to their children. Zhang says it can also be used to create rejuvenated eggs. He calls it a “cure for infertility” and says Darwin Life will begin offering it to women aged 42 to 47, an age at which the chance of becoming pregnant declines dramatically.
Zhang is a highly skilled fertility provocateur who last year, in Mexico, carried out the first successful use of the technique, which employs delicate hollow needles to swap the chromosomes of a woman’s egg into the egg of a donor.
The process is controversial because it is largely untested and because some consider it a form of genetic modification. In March, after lengthy public debate, the U.K. became the first country to allow a fertility clinic to offer a similar treatment, but only when a couple is at very high risk of having a child with a life-threatening genetic disease.
The technique remains illegal in the U.S., and Zhang says Darwin Life will offer it only overseas for now. He says the company is assessing a handful of hopeful women over 40 who may be able to benefit.
The formation of the company is alarming some observers, who say the process is too new to commercialize widely and could create increased demand for donors to supply eggs.
“This is a biologically extreme and risky procedure,” says Marcy Darnovsky, executive director of the Center for Genetics and Society, a group that questions advances in biotechnology. “If you’re talking about using these techniques for age-related infertility, that’s really moving the human experimentation to a very large scale.”
In a document filed with the U.S. Securities and Exchange Commission, Darwin Life, incorporated at the same New York City location as Zhang’s clinic, said it had raised $1 million in an initial round of funding. Zhang declined to identify the investors.
Sometimes known as a “three-parent baby” technique, the procedure acts to combine one woman’s genes with the youthful contents of another’s egg, notably energy-making structures called mitochondria. Because mitochondria possess their own small number of genes, the resulting child has three genetic parents.
The cause of age-related infertility is still unknown, but Zhang and some other experts believe that faulty mitochondria are a reason why older women can’t easily produce viable embryos. That’s why Zhang thinks his technique of harnessing a young egg will help.
Last year, Zhang and his team performed spindle nuclear transfer on the eggs of a woman with a rare neurological disease called Leigh syndrome, caused by defective mitochondria. The parents, a Jordanian couple, previously had two children who died from the disease.
Zhang started by obtaining an egg from a donor and removing its nucleus. Into this genetically hollowed-out egg, he then injected the chromosomes of the Jordanian woman, which he had obtained from one of her eggs. Zhang then fertilized the reconstructed egg with the father’s sperm, as would occur in standard in vitro fertilization, or IVF.
Although that embryo was created in New York City, it was transferred to the woman’s uterus in Mexico because of a U.S. law that effectively outlaws the use of the technology here. A healthy baby boy was born in April 2016.
Concerns over “designer babies” led Congress to forbid the U.S. Food and Drug Administration from considering research applications involving any type of genetically modified embryos, including those made using the nuclear transfer technique.
Because of that regulatory red tape, Zhang says Darwin Life will continue making embryos in the U.S. but will perform the medical procedures at New Hope’s clinic in Guadalajara, Mexico, or in other countries he believes will embrace the idea.
“For now, our nuclear transfer technique is very much like an iPhone that’s designed in California and assembled in China,” he says.
Robin Lovell-Badge, a developmental biologist at the Francis Crick Institute in London, says Zhang’s effort to commercialize the technology is “concerning” because the procedure carries potential risks. Faulty mitochondria can still end up in the resulting embryo and there’s also a chance of genetic incompatibility.
Zhang’s own report of the Mexico birth, published in April, reveals that some damaged DNA from the mother was unintentionally transferred into the donor egg, which could lead to health problems for the child later in life.
Lovell-Badge was part of an expert panel in the U.K. that in November recommended that mitochondrial replacement therapy should be permitted there, reasoning it was worth the risk, but only to avoid debilitating genetic disease.
“I understand the desire of women to have children and to have genetically related children,” says Lovell-Badge. “But the risk-benefit ratio is different. It’s a question of having no children or having a child that is suffering from a terrible disease. It’s not quite the same.”
Ainsley Newson, associate professor of bioethics at the University of Sydney, also thinks that “limiting the use of mitochondrial replacement to prevent disease—under strict regulation and a research protocol, such as in the United Kingdom—is prudent.”
In the U.S., the federal government not only bars the procedure but also prohibits any funding into research on fertility treatments or human embryos. Sean Tipton, a spokesperson for the American Society for Reproductive Medicine, a trade group representing doctors, says Zhang’s choice to offer the process overseas is a result of those restrictions.
“When our government buries its head in the sand by refusing to let the FDA even evaluate this kind of procedure, we are going to see these efforts move to places where the oversight might not be done in the manner we would like,” says Tipton.
Zhang says Darwin Life will charge $80,000 to $120,000 for spindle nuclear transfer. He estimates there is a market worth $2 billion per year considering how many women can’t conceive because of their age. Of about 8,700 IVF attempts by women over 42 in the U.S. in 2014, less than 4 percent led to a successful pregnancy, showing how much age weighs against the odds.
Newson worries that marketing these procedures to infertile women equates to “selling hope to often vulnerable women.”
But IVF is already a costly, physically draining, and uncertain undertaking. The average price of an IVF treatment runs about $12,400 in the U.S., according to Tipton’s organization, and many women undergo two or three rounds of treatment before they become pregnant.
Zhang says women who go through IVF are already committed to getting pregnant. For that reason, Zhang doesn’t think they will be dissuaded from traveling to another country to get the procedure. He says Darwin Life has already received hundreds of inquiries from prospective parents.
Zhang’s breakaway plans don’t stop at spindle nuclear transfer. He says a future step will be to combine the technique with editing genes, so that parents can select hair or eye color, or maybe improve their children’s IQ.
“Everything we do is a step toward designer babies,” Zhang says of Darwin Life. “With nuclear transfer and gene editing together, you can really do anything you want.”