The study, which makes use of a technology called mitochondrial donation, has been described as a “tour de force” and “a remarkable accomplishment” by others in the field. Mitochondrial donation was first made legal in the UK in 2015. Newcastle Fertility Centre at Life launched a trial of mitochondrial donation in 2017 with the aim of treating 25 women a year. That’s despite the fact that other teams elsewhere have used mitochondrial donation to help people achieve pregnancy. A New York–based doctor used a type of mitochondrial donation to help a Jordanian couple conceive in Mexico in 2016.