Doctors in the United Kingdom have delivered a baby with DNA from three people using a special in-vitro fertilisation (IVF) technique.

The technique is known as mitochondrial donation treatment, or MDT, reported The Guardian.

It uses tissue from the eggs of healthy female donors to create IVF embryos that would be devoid of harmful mutations a mother may potentially pass on to her child.

The embryos combine sperm and egg from the biological parents with tiny battery-like structures called mitochondria from the donor’s egg.

It is for this reason, the resulting baby has DNA from the biological parents – amounting to more than 99.8 per cent – plus a small amount of genetic material from the donor.

The process has led to the phrase “three-parent babies”.

MDT is also known as mitochondrial replacement therapy (MRT).

The research on MDT was pioneered in the UK by doctors at the Newcastle Fertility Centre.

The research aimed to prevent women with mutated mitochondria from passing on genetic disorders to their babies.

Humans inherit all their mitochondria from their mothers. This means that a woman’s harmful mutations can affect all the children she has.

For these affected women, natural conception becomes a gamble.

Some babies may be born healthy because they inherit only a minimal amount of the mutated mitochondria.

But in some cases, far more of such material may be transmitted, resulting in the development of severe and often fatal diseases.

The MDT procedure is not without risks, however.

In some cases, recent research has found, the tiny number of harmful mitochondria that pass from a mother’s egg to the donor’s egg can multiply when the baby is in the womb.

The reason for this phenomenon remains unclear, said Dr Dagan Wells, professor of reproductive genetics at the University of Oxford who took part in the research.

Doctors at the Newcastle clinic have not released details of the births from its MDT programme due to patient confidentiality.

But the UK’s Human Fertilisation and Embryology Authority confirmed that a small number of babies have now been born in the UK after MDT.

As of late April 2023, the number of births was “less than five”, the regulator said. No other details were provided.

Due to the small number of reported cases, Dr Wells said it is too soon to draw any firm conclusions about the procedure’s safety or efficacy. He said a long-term follow-up of the MDT babies would be necessary.

Meanwhile, a UK charity that helps people affected by infertility and genetic conditions said the technology needs to be used in a “measured and carefully regulated way” while it is assessed.

It also highlighted the need to respect the privacy of children born this way and their parents.

The UK is not the first country to create babies from MDT.

In 2016, a United States doctor announced the world’s first MDT birth. That doctor had treated a Jordanian woman who carried mitochondrial mutations that cause a fatal condition called Leigh syndrome.

The treatment was performed in Mexico. Prior to the procedure, the woman had four miscarriages and two children. One died aged six, and the other lived for only eight months.