A groundbreaking in vitro fertilization (IVF) trial has resulted in the world’s first baby born with a reduced risk of inheriting mitochondrial diseases, marking a significant advancement in reproductive medicine.
Announced on July 17, 2025, by a consortium of UK scientists, the procedure, known as mitochondrial donation treatment (MDT), involves transferring healthy mitochondrial DNA from a donor egg into an embryo created from the parents’ sperm and egg. This technique, first legalized in the UK in 2015, addresses mutations affecting one in 6,000 babies, which can lead to severe conditions like Leigh syndrome, impacting the brain and muscles.
The trial, conducted at a leading London fertility clinic, successfully delivered a healthy baby girl on July 10, 2025, to a mother with a known mitochondrial disorder. Unlike traditional IVF, MDT adds about 37 genes from the donor, less than 0.2% of the child’s total DNA, while preserving the parents’ genetic identity.
Researchers report a 90% reduction in mutation carryover, though risks of reversion, where mutated mitochondria multiply, remain under study. Critics, including some ethicists, raise concerns about long-term effects and the “three-parent” label, but the family and medical team hailed it as a lifeline. The success could expand access, though costs, £3,000-£9,000 per cycle in the UK, pose barriers, prompting calls for broader NHS funding.