UK’s Three-Parent IVF Leads to Eight Healthy Babies, Says New Study

In a major medical breakthrough, doctors in the UK have announced that eight healthy babies have been born using a groundbreaking IVF technique involving DNA from three people. The goal? To prevent children from inheriting deadly mitochondrial diseases from their mothers. The findings were officially published this Wednesday in The New England Journal of Medicine.

Why This Was Needed

Although we inherit DNA from both parents, mitochondria—the cell’s energy center—are passed down only through the mother. If mutations occur in these mitochondria, it can lead to severe genetic disorders, which may cause symptoms like muscle weakness, seizures, developmental delays, organ failure, and in some cases, even death.

These conditions are uncommon but dangerous, showing up in about 1 out of every 5,000 babies. Since mitochondria are the powerhouses of our cells, any disturbance can disrupt how the body functions and develops.

Liz Curtis, whose daughter Lily died of a mitochondrial condition, told the media, “The diagnosis turned our world upside down and yet nobody could tell us very much about it, what it was or how it was going to affect Lily.”

What Is the Treatment

The treatment was first allowed in 2015 when the UK amended its laws. Back in 2017, the country’s fertility regulator granted the first license to a clinic at Newcastle University.

This IVF-based technique uses DNA from three individuals:

• The mother’s egg

• The father’s sperm

• And a small amount of healthy mitochondrial DNA contributed by a donor egg

Here's how the process works:

• The mother’s egg is fertilized with the father’s sperm

• The nucleus (which contains most of the parents’ DNA) is then removed from this fertilized egg

• It is transferred into a donor egg that has had its own nucleus removed, but contains healthy mitochondria

• The resulting embryo has the parents’ DNA and the donor’s mitochondria (about 0.1% of total DNA)

• The embryo is then implanted into the woman to establish pregnancy

This has led to the nickname “three-parent baby”, though the baby’s traits and identity still come entirely from the parents.

What Are the Results

The treatment was carried out at Newcastle Fertility Centre in North East England. A total of 22 women received the procedure, which led to the birth of eight babies—four boys and four girls. Their current ages range from under six months to over two years.

• In six of them, the faulty mitochondrial DNA was reduced by 95 to 100 percent.

• In the remaining two, the levels were reduced by 77–88%, which is still below the disease-causing threshold

Genetic tests later showed that the babies had little to no traces of mutated mitochondria. All are currently healthy and are being closely monitored for their long-term development.

As of July 2025, 35 patients have been approved to undergo this technique in the UK. However, each case still needs individual clearance from the fertility regulator.

Reactions From Families and Experts

Dr. Andy Greenfield, a reproductive health expert at the University of Oxford, in conversation with the media, called the development “a triumph of scientific innovation.”

In an interview with The Guardian, Robin Lovell-Badge, a principal scientist at the Francis Crick Institute in London, acknowledged the slow pace of the process but said the caution was necessary.

While the UK amended its laws to allow this technique nearly a decade ago, the US still prohibits its clinical use due to strict regulations against heritable genetic modification. Outside of the UK, Australia is one of the few other countries that have officially adopted this method.

Why It Matters

The birth of these babies is not just a scientific first; it is a lifeline for families who previously had no options. For parents at risk of passing on devastating mitochondrial disorders, this technique offers real hope without altering the child’s core identity.

As more countries consider regulating and approving this procedure, the UK’s cautious but successful rollout could serve as a global model. And for now, it has already changed eight lives and counting.

Reference:

1. Hyslop, Louise A., Emma L. Blakely, Magomet Aushev, Jordan Marley, Yuko Takeda, Angela Pyle, Eilis Moody, et al. “Mitochondrial Donation and Preimplantation Genetic Testing for mtDNA Disease.” New England Journal of Medicine, July 16, 2025. Accessed July 18, 2025. https://doi.org/10.1056/nejmoa2415539.

(Rh/Pooja Bansal/MSM/)