After the British government approved an innovative method for creating a “three-parent baby” in 2015, several children have already been born in the country thanks to this method of artificial insemination. The UK’s Human Fertilization and Embryology Authority (HFEA) told The Guardian newspaper in response to journalists’ inquiries. The exact number is not being disclosed for confidentiality reasons, but according to the agency, there have been fewer than five such babies.
Scientists at Newcastle University have developed a revolutionary method of three-person IVF. It is called “Mitochondrial Replacement Therapy” and it allows the prevention of incurable genetic disorders in children whose mothers are carriers of mitochondrial diseases. This method of artificial insemination uses only 0.1% of the female donor’s DNA, which is why scientists insist that the child has only two parents, not three. It involves combining the mitochondria of a healthy female donor with the nucleus of the egg of the child’s mother. Mitochondria – Part of the cell structure responsible for supplying energy to the cell. They are transmitted only through the maternal line, so only female donors participate in the procedure. Mitochondria have their own DNA, but, as scientists insist, it does not affect the appearance or other personal characteristics of the future baby. Therefore, despite the presence of donor mitochondria, the child will resemble only the parents.
Mitochondrial defects in the mother’s cells lead to the birth of children with severe diseases: they can suffer from impaired brain function, muscular dystrophy, heart defects and blindness. In an interview with the BBC, Professor Doug Turnbull, who led the research at Newcastle University, explained that in the most critical cases, children with these diseases die within the first 48 hours of life. “But this is rare. More often, we observe people with a high degree of disability for decades,” the professor added. According to scientists, approximately one in 6000 newborns worldwide is born with a mitochondrial disease.
Three-parent IVF involves extracting the nucleus from the mother’s fertilized egg and transplanting it into a fertilized donor cell with healthy mitochondria that has had its nucleus removed. “The news that a small number of children with donor mitochondria have been born in the UK is the next step in the slow and cautious process of evaluating and improving mitochondrial donation, which is likely to continue,” says Sarah Norcross, director of the Progress Educational Trust, which helps people suffering from infertility. There has been no comment from the scientists at Newcastle University, so details of the success of the technique are unknown. “It will be interesting to find out how successful mitochondrial replacement therapy works in practice, whether children are cured of mitochondrial disease, and whether there is a risk of developing disease in adulthood,” said Robin Lovell-Badge, a specialist in developmental genetics at the Francis Crick Institute in the UK.
Earlier, scientists from Newcastle warned that there is a risk of “reversion” if some of the mother’s defective mitochondria end up in the final egg cell and subsequently increase in number. In 2015, when the UK government made the decision to legally allow mitochondrial replacement therapy, it was estimated that up to 150 children could be born in the UK thanks to this procedure. After that, however, there was a lull and, as reported by The Guardian, the process slowed down due to the pandemic when there was a shortage of donors willing to work with prospective parents. As a result, the world’s first baby conceived in this way was born in Mexico, thanks to a procedure performed in the United States. He was born to a woman from Jordan who was a carrier of Leigh Syndrome, a disease that affects the central nervous system in humans. She is healthy herself, but has lost two children due to defective mitochondria.
Scientists at the New Hope Infertility Treatment Center in New York helped the couple. When the Newcastle scientists announced their research and launched an initiative to get the procedure approved by law in the UK, they had opponents. In particular, representatives of the Roman Catholic and Anglican churches considered three-parent IVF to be unethical and unsafe. In addition, some human rights activists have expressed concern that three-parent ART (assisted reproductive technology) will enable the creation of so-called “designer babies”. According to them, such a procedure will allow parents to “control” the child’s appearance – for example, to choose the color of eyes and skin.