Doctors are declaring medical history has been made after a baby was born in Greece that was produced from three people.
The baby boy was produced using experimental IVF treatment that uses an egg from the mother, sperm from the father, and another egg from a donor woman.
The child, who weighed 6lbs at birth, and his 32-year-old mother, are both said to be in good health.
The IVF treatment used to produce the baby was developed to help families affected by deadly mitochondrial diseases which are passed down from mother to baby.
Mitochondria are the tiny compartments inside nearly every cell of the body that convert food into useable energy.
Mitochondrial diseases make these compartments defective so the the treatments combines the mother’s DNA with a donor’s mitochondria – with the hope of preventing disease.
However, some experts believe mitochondria may have a role in a successful pregnancy as well.
Fertility doctors in Greece and Spain said the birth was “medical history”.
Dr Panagiotis Psathas, president of the Institute of Life in Athens, said: “A woman’s inalienable right to become a mother with her own genetic material became a reality.
“We are very proud to announce an international innovation in assisted reproduction, and we are now in a position to make it possible for women with multiple IVF failures or rare mitochondrial genetic diseases to have a healthy child.”
However, some UK experts believe the technology raises ethical issues.
Tim Child, from the University of Oxford and the medical director of The Fertility Partnership, said: “I’m concerned that there’s no proven need for the patient to have her genetic material removed from her eggs and transferred into the eggs of a donor.
“The risks of the technique aren’t entirely known, though may be considered acceptable if being used to treat mitochondrial disease, but not in this situation.
“The patient may have conceived even if a further standard IVF cycle had been used.”
Another 24 women are taking part in the trial and eight embryos are ready to be implanted.