The experimental procedure, which used DNA from the patient, sperm from the father, and an egg from a donor woman, was developed to help families affected by deadly mitochondrial diseases inherited from mothers.

In this case it was used to help a 32-year-old patient in Greece who had endured four unsuccessful cycles of IVF. She gave birth to a baby boy weighing 6 pounds (2.9 kg) on April 9. The mother and child are said to be in good health.