What Are Three-Parent Babies? UK Regulator Grants Licence For IVF Technique

Authorities in the U.K. on Thursday granted the country’s first-ever license to create babies using a “three-parent” in-vitro fertilization (IVF) technique. The license, granted to a clinic at Newcastle University, would allow doctors to carry out what’s known as a pronuclear transfer to reduce the risk of mitochondrial diseases.

“I can confirm today that the HFEA has approved the first application by Newcastle Fertility at Life for the use of mitochondrial donation to treat patients,” Sally Cheshire, the chairwoman of Human Fertilisation and Embryology Authority — the body that oversees and regulates fertility treatments and research in the country — said in a statement released Thursday. “Patients will now be able to apply individually to the HFEA to undergo mitochondrial donation treatment at Newcastle, which will be life-changing for them, as they seek to avoid passing on serious genetic diseases to future generations.”

Read: 'Three-Parent Babies' Approved In UK

Human cells contain two types of DNA — nuclear DNA that’s found in the nucleus, and mitochondrial DNA, which is present in the cells’ energy-producing mitochondria. Unlike nuclear DNA, which is inherited in equal quantities from both parents, the mitochondrial DNA — present outside the nucleus — is inherited only from the mother.

Defects in mitochondrial DNA affect about 1 in every 5,000 births and can lead to severe, and in some cases, even fatal, birth defects. This can be prevented by replacing the defective mitochondrial DNA with a healthy one, which can be achieved using the pronuclear transfer technique that the HFEA approved in December.

“Many years of research have led to the development of pronuclear transfer as a treatment to reduce the risk of mothers transmitting disease to their children,” Mary Herbert, a professor of reproductive biology at Newcastle Fertility Centre and Newcastle University, said in a statement. “It’s a great testament to the regulatory system here in the UK that research innovation can be applied in treatment to help families affected by these devastating diseases.”

The IVF technique involves removing the pronuclei — the nucleus of the sperm and the egg during the process of fertilization — from an embryo containing the mother’s unhealthy mitochondria. These pronuclei are then inserted in a donor embryo containing a healthy mitochondria.

A child born through this technique would have genes from three “parents” — one male (the father) and two females (the mother and the donor).

Opponents of the procedure have not only raised ethical objections by questioning the psychological and social implications of children with three genetic parents, they have also said the technique should be avoided as the medical risks associated with changing mitochondrial DNA have yet to be fully understood.

For instance, in the U.S., despite cautious approval from the National Academies of Sciences, Engineering and Medicine committee, Congress currently bans such procedures for clinical use.

So far, the only known instance of a baby being born through this three-person technique occurred last year in Mexico, when a team of U.S. doctors performed the procedure on a Jordanian couple. The mother's mitochondria contained genes for Leigh syndrome — a neurological disorder than can prove fatal in early childhood.