The UK fertility regulator, Human Fertilisation and Embryology Authority (HEFA) has confirmed that a baby has been born with DNA from three people for the first time in the country. The child’s DNA is primarily from their two parents, with a small percentage (0.1%) coming from a donor woman. The technique was developed to prevent devastating mitochondrial diseases, which can be fatal within hours or days of birth and have no cure. While fewer than five such babies have been born, no further information has been disclosed.

Mitochondria are small compartments in almost every cell of the body that convert food into usable energy. If the mitochondria are defective, they can cause brain damage, muscle wasting, heart failure, and blindness. These diseases are only passed down by the mother, which is why mitochondrial donation treatment is a modified form of IVF that uses healthy mitochondria from a donor egg.

While the resulting children inherit DNA from their parents and a small amount from the donor, this only affects the effectiveness of the mitochondria and not the child’s other characteristics or traits. This change is permanent and will be passed down through generations, but it does not constitute a “third parent.”

The technique was pioneered in Newcastle, and laws were introduced to allow the creation of “three-person babies” in the UK in 2015. However, the UK did not immediately proceed with the technique, and the first baby born via this method was to a Jordanian family receiving treatment in the US in 2016. This birth represents a step forward in the cautious process of refining mitochondrial donation.

According to the Human Fertilisation and Embryology Authority (HFEA), as of April 20, 2023, “less than five” babies have been born in the UK using donated mitochondria. The HFEA has not disclosed the exact number to protect the families’ identities. This information was released after the Guardian newspaper made a Freedom of Information request.