The birth of babies created with DNA from three individuals has stirred significant attention worldwide. Recently, the UK announced the arrival of eight babies conceived through a pioneering IVF technique involving DNA from three people.
This method, designed to prevent mitochondrial diseases passed from mother to child, offers hope to families facing genetic challenges. However, the story of “three-person IVF” stretches back decades and spans continents, revealing a path filled with both promise and caution.
Understanding the Science Behind Three-Person IVF
In this technique, the vast majority of the child’s DNA comes from the intended mother and father—specifically from the nuclei of their egg and sperm cells. The twist lies in the inclusion of mitochondrial DNA (mtDNA) from a third donor.
Unlike nuclear DNA, mtDNA is tiny, containing just 37 genes, all responsible for the cell’s energy production. This small DNA fraction is inherited almost exclusively from the mother and can sometimes carry harmful mutations that cause mitochondrial diseases. By replacing faulty mitochondria with healthy ones from a donor, the procedure aims to prevent these debilitating conditions.
Freepik | Experts call it "three-person IVF" because the donor's genetic input is only mitochondrial DNA, not influencing traits.
Many experts prefer calling this process “three-person IVF” rather than “three-parent babies,” as the donor’s genetic contribution is limited to mitochondrial DNA, which doesn’t influence traits like eye color or height. Critics argue that the donor should not be labeled a parent because their genetic input represents only a tiny fraction of the child’s entire genome.
Early Attempts and Challenges
The first reported attempts at this form of IVF trace back to the 1990s when Jacques Cohen and his team in New Jersey experimented with injecting cytoplasm containing healthy mitochondria into eggs of women experiencing infertility
. Seventeen babies were born through this method, but concerns arose after two fetuses developed genetic abnormalities and one child showed developmental issues. This prompted the U.S. Food and Drug Administration to halt the research in 2002.
These early outcomes sparked debate about the safety of mixing mitochondrial DNA from two sources. Some researchers worried that combining mtDNA from different individuals might lead to unpredictable effects, and the exact reasons behind the abnormalities remain unclear.
Renewed Efforts and Ethical Questions
In 2016, John Zhang at the New Hope Fertility Center introduced a refined method. He extracted the nucleus from the intended mother’s egg and implanted it into a donor egg that had its nucleus removed but retained healthy mitochondria. The egg was then fertilized with sperm from the intended father.
Zhang performed this procedure in Mexico due to legal restrictions in the U.S., leading to the birth of a healthy baby boy to a Jordanian couple. This success demonstrated the technique’s potential to prevent fatal mitochondrial diseases.
Nevertheless, Zhang’s approach ignited ethical debates. Critics questioned the lack of oversight and whether it was appropriate to conduct such procedures outside regulated environments. Meanwhile, the UK moved toward legalizing mitochondrial donation, with licensed trials beginning in 2017, signaling a more structured path forward.
Global Developments and Continued Discoveries
Ukraine has become a notable center for three-person IVF, with clinics reporting dozens of births resulting from mitochondrial donation techniques. While some clinics openly share their outcomes, others remain discreet, making it difficult to assess the full impact. In 2020, a trial in Greece involving 25 patients led to seven births, expanding the scope of the procedure to address infertility as well as genetic diseases.
However, challenges persist. Some babies born through these methods still inherit a small percentage of mutated mitochondria from their mothers, a phenomenon called “reversal.” This raises questions about the long-term effectiveness of mitochondrial replacement in completely eliminating disease risk.
What the Future Holds for Three-Person IVF
Instagram | pw_meded | New UK births mark the success of an eight-year trial against mitochondrial disease.
The recent UK announcement celebrates the birth of babies born through an eight-year trial designed to reduce mitochondrial disease. Yet, this progress comes with caveats. The procedure does not guarantee that all mitochondrial mutations are eliminated, and scientists continue to monitor these children’s health outcomes carefully.
The evolving field of mitochondrial donation challenges traditional ideas about genetics and parenthood. It raises important scientific, ethical, and legal questions, especially as technology pushes boundaries once thought impossible. As the community learns from each birth, the goal remains clear: to provide families with safer options to prevent inherited diseases without compromising ethical standards.
Reflecting on the Impact of Three-Person IVF
The story of three-person IVF is far from over. It blends scientific innovation with real human hopes and struggles. While the method offers a promising way to prevent serious mitochondrial diseases, it also reveals the complexities of manipulating genetics at a fundamental level. The births of children through this technique mark a significant step in reproductive medicine, but they remind us that with new possibilities come new responsibilities.
Continued research, transparent sharing of results, and thoughtful ethical consideration will shape how this technology develops. It holds the potential to reshape the future of family-building, offering hope to many, yet demanding careful attention to ensure safety and fairness.