Despite the promising outcomes of the two techniques, pronuclear transfer and spindle transfer, mitochondrial gene replacement raises ethical and social concerns.
According to Darnovsky, an executive director of the Center for Genetics and Society, the technique procedures would involve modification of the germline, and modifications would pass on to subsequent generations. Using human embryos in vitro research is controversial because embryos are created specifically for research and the financial compensation of egg donors.
Implications for identity is another ethical concern that has psychological and emotional impacts on a child's life regarding of a person's sense of identity. It debates whether the genetic make-up of children born as a result of mitochondrial replacement affect their emotional well-being when they are aware that they are different from other healthy children conceived from two parents. Safety and efficacy of mitochondrial DNA replacement are still unanswered.
Opponents argue that scientists are "playing God" and that children with three genetic parents may suffer both psychological and physical damage. These critics include Alison Cook of Great Britain's Human Fertilisation and Embryology Authority, who argues that bans were "written to protect the welfare of the embryo and the child."
On the other hand, New York University researcher James Grifo, a critic of the American ban, has argued that society "would never have made the advances in treating infertility that we have if these bans had been imposed 10 years" earlier.
