This week, news emerged from the UK about the birth of eight babies conceived through an experimental form of IVF that incorporates DNA from three individuals—a technique intended to prevent the transmission of mitochondrial diseases from mother to child. Known as mitochondrial donation or ´three-person IVF,´ the procedure supplements the nuclear DNA from the intended parents with healthy mitochondrial DNA from a donor, aiming to eliminate harmful mitochondrial mutations while preserving the family´s genetic lineage.
However, the children born in the UK are not the first of their kind. Since the 1990s, several teams worldwide have experimented with variations of three-person IVF. The earliest documented cases involved injecting cytoplasm rich in mitochondria from donor eggs into eggs of mothers with fertility challenges. While seventeen babies were born from these early efforts, some presented genetic abnormalities, raising ethical and biological concerns. The US Food and Drug Administration subsequently halted such research in 2002, but this did not quell global scientific interest. In 2016, a well-publicized case saw John Zhang facilitate a successful three-person IVF procedure for a Jordanian couple in Mexico, circumventing US laws. Ukraine and Greece have also hosted significant numbers of such births through clinical trials addressing both mitochondrial disease prevention and infertility.
The approach, though promising, is not without controversy or complication. Debates over terminology reflect deeper questions about genetics, parenthood, and ethics, as mitochondrial DNA comprises only 37 genes and represents a minuscule fraction of a child’s total genetic material. Some scientists argue that calling the outcome a ´three-parent´ baby is misleading. Moreover, the technique is not foolproof. In both the UK and other international cohorts, some babies were found to carry a non-negligible proportion of mutated mitochondria despite the intervention. While the births in the UK mark progress in regulated, evidence-based application, the global history underscores a pattern of variable oversight and outcomes. As the technology advances, experts stress the need for continued vigilance—robust monitoring, transparency, and ethical reflection remain paramount, as the true long-term impacts on children born via three-person IVF are still unfolding.