In 2016, John Zhang and a mixed team of scientists from Mexico and New York used the spindle transfer technique to help a Jordanian woman to give birth to a baby boy. The mother had Leigh disease and already had four miscarriages and two children who had died of the disease. Valery Zukin, director of the Nadiya clinic in Kyiv, Ukraine, reported in June 2018 that doctors there had used the pronuclear transfer method of MRT to help four women give birth (three boys and a girl) and three women to become pregnant (one from Sweden); the team had 14 failed attempts.  In January 2019 it was reported that seven babies had been born using MRT. The doctors had first gotten approval from an ethical committee and a review board of the Ukrainian Association of Reproductive Medicine and the Ukrainian Postgraduate Medical Academy, under the auspices of the Ukrainian Ministry of Healthcare; there was no law in the Ukraine against MRT. One of the first children, a boy, was born to a 34-year-old woman in January 2017, and genetic test results were reported as normal. In August and October 2017 the British HFEA authorized MRT for two women who had a genetic mutation in their mitichondria that causes myoclonic epilepsy with ragged red fibers. In January 2019, Embryotools, Barcelona, Spain announced that a 32-year-old Greek woman had become pregnant using the spindle transfer technique. MRT was not legal in Spain so they had performed the trial in Greece where there was no law against MRT. They were helped by the Institute of Life in Athens, Greece and had obtained approval from the Greek National Authority of Assisted Reproduction. The pregnant Greek woman had already had four failed IVF cycles and surgery twice for endometriosis.
In August 2017, in a letter to two clinics, including Zhang's, the FDA warned that the technique should not be marketed in the U.S.