Doctors in Britain have achieved a major advance in reproductive medicine with the birth of eight healthy babies conceived through a revolutionary procedure that uses DNA from three individuals. The technique aims to prevent children from inheriting incurable genetic disorders caused by mitochondrial mutations.

“Mitochondrial disease can have a devastating impact on families,” professor Doug Turnbull of Newcastle University said in a Wednesday press release. “Today’s news offers fresh hope to many more women at risk of passing on this condition who now have the chance to have children growing up without this terrible disease.”

The mothers who underwent the procedure were at high risk of passing on life-threatening diseases due to abnormal mitochondria. Mutations in the mitochondria affect about one in 5,000 newborns globally, often leading to conditions that compromise the brain, heart, and muscles. Symptoms in children range from developmental delays to severe organ dysfunction, which can lead to premature death.

The achievement has been years in the making. The United Kingdom became the first country to legalize mitochondrial donation treatment in 2015. Two years later, the fertility regulator granted the first license to Newcastle University’s clinic, where the procedure was pioneered. Since then, researchers and affected families have awaited the results of the groundbreaking endeavor.

The eight babies born through this process — four boys and four girls, including a set of identical twins — have shown no signs of the mitochondrial diseases they were at risk of inheriting, offering immense hope for families affected by similar genetic disorders, the scientists said in their statement.

Mitochondrial donation treatment involves an intricate process of fertilizing the mother’s egg with the father’s sperm and then transferring the genetic material from the nucleus into a fertilized donor egg. The donor egg, which has had its nucleus removed, provides healthy mitochondria while the genetic identity of the child remains that of the biological parents. 

The fertilized egg is then implanted into the mother’s womb, allowing pregnancy to proceed.

The cutting-edge technology specifically helps women who have mitochondrial mutations in all their eggs. For those with milder mutations, pre-implantation genetic testing is an alternative method that identifies eggs with minimal risks of passing on disorders.

Published in two papers in the New England Journal of Medicine, the success story offers detailed insights into the health of the babies. For families who have undergone years of uncertainty, the treatment represents more than scientific advancement. 

The mother of one of the babies eloquently captured the promise of the breakthrough when she said, “All we ever wanted was to give our child a healthy start in life. After years of uncertainty, this treatment gave us hope — and then it gave us our baby. We’re overwhelmed with gratitude. Science gave us a chance,” she said.