Overview

• Six of the eight babies born through pronuclear transfer at Newcastle Fertility Centre had mutated mitochondrial DNA cut by 95–100%, and two showed reductions of 77–88%.
• A ninth pregnancy remains ongoing under the Human Fertilisation and Embryology Authority’s sole licence for mitochondrial donation in the UK.
• Results published in the New England Journal of Medicine offer the first detailed, peer-reviewed evidence of the technique’s safety and efficacy.
• Researchers have established long-term follow-up protocols, including developmental assessments at age five, to monitor potential late-emerging effects.
• The UK’s 2015 regulatory framework was the first to explicitly legalise mitochondrial donation under strict ethical and clinical oversight.