Legislation passed by the House of Lords in 2015 enabled mitochondrial replacement in the United Kingdom for the prevention of severe mitochondrial diseases. Regulation was delegated to the Human Fertilisation and Embryology Authority (HFEA) which granted its first licence to Newcastle upon Tyne Hospitals NHS Foundation Trust in 2017. Mitochondrial transfer, or “babies with three parents” as it was known in the lay press, is now a national commissioned NHS service in England and Wales. In 2016, it was reported that a woman gave birth to a healthy boy in Mexico following oocyte spindle transfer to prevent the inheritance of a mitochondrial DNA (mtDNA) disorder.1 Of particular concern, however, is that the technique has become available for the “treatment” of infertility at many fertility centres world-wide.2