UK moves a step closer to being first country in world to allow “three parent babies”

BMJ 2013; 346 doi: (Published 21 March 2013) Cite this as: BMJ 2013;346:f1899
  1. Ingrid Torjesen
  1. 1London

The United Kingdom looks increasingly likely to become the first country in the world to allow the creation of babies from two women and a man after the Human Fertilisation and Embryology Authority (HFEA) today revealed the results of its government commissioned public consultation on mitochondrial transfer and its analysis of the safety and efficacy issues.

Last year ministers asked the HFEA to conduct a public consultation on attitudes to the use of a three person technique of in vitro fertilisation (IVF) that could prevent debilitating and fatal “mitochondrial” diseases being passed from mother to child. The consultation found public support for use of the technique.1

The government also asked the HFEA to conduct a scientific assessment to review the safety and efficacy of mitochondrial replacement and to consider the practical implications of allowing the use of the technique. It found no evidence indicating that the techniques were unsafe.2

Mitochondrial diseases affect the organs that need the most energy, such as the heart, muscles, and brain. An estimated 12 000 people in the UK have a mitochondrial disease, and about 100 babies are born each year with a severe form of the diseases, many of whom die in infancy.3

Mitochondrial DNA is inherited solely through the maternal line, and use of mitochondrial transfer could help a few dozen of these women each year to have a healthy baby.

Mitochondrial diseases can be caused by faults in the genes within a cell’s nucleus that are needed for mitochondrial function or by faults in the small amount of DNA that exists within the mitochondria themselves. It is this second form of mitochondrial disease that could potentially be avoided through use of one of two new mitochondrial transfer techniques—pro-nuclear transfer or maternal spindle transfer—that the HFEA considered.

In pro-nuclear transfer the genetic material belonging to both the father and mother contained in the pro-nucleus is removed from the fertilised egg before it has developed into a multicell embryo and is transferred into a fertilised donor egg that contains healthy mitochondria and has had its own pro-nucleus removed.

In maternal spindle transfer a spindle shaped structure containing the mother’s nuclear DNA is first removed from one of her eggs and transplanted to a donor egg with healthy mitochondria and that has had its own spindle removed. This egg is then fertilised by the intended father’s sperm.

In both techniques the resulting embryo possesses nuclear DNA from its mother and father and mitochondrial DNA from the donor.

Neva Haites, professor of medical genetics at the University of Aberdeen and chairwoman of the expert group overseeing the consultation and the panel that produced the scientific report, told a press briefing, “Broadly speaking the public was in favour of these novel techniques being translated into treatments.” However, she added that a minority argued against the use of pro-nuclear transfer because it involved the manipulation and disposal of embryos.

She said, “The prevailing view of the majority . . . was that the outcome of the technique—that is, a healthy child free of faulty mitochondria, free of potential serious disease—outweighed the possible consequences of changing the germ line.”

Robin Lovell-Badge, a member of the expert group overseeing the consultation and of the panel that produced the scientific report and also head of the Division of Stem Cell Biology and Developmental Genetics at the Medical Research Council’s National Institute for Medical Research, London, told the briefing, “The panel concluded that there is still no evidence to suggest that the techniques are unsafe. There is currently more published evidence available to support the MST [maternal spindle transfer] technique than the PNT [pro-nuclear transfer] technique, but there is still insufficient evidence to recommend one technique over the other.”

He said that the panel had recommended further experiments on safety, efficacy, and the extent of carryover of maternal mitochondria before either technique was introduced into clinical practice. But he said that the panel’s view was that the techniques may in the future be preferable to other treatment options such as preimplantation genetic diagnosis or embryo testing.

He added, “Safety is absolutely not a black and white issue. In reproductive medicine in particular it is not possible to be absolutely certain about the consequences of any new treatment until children are born.”

It is now up to the health secretary, Jeremy Hunt, to decide draft regulations that would allow mitochondrial transfer and put them before parliament.

At a meeting on Wednesday the HFEA decided that, if the government drafted regulations, certain policies and safeguards should be put into place. Clinics wishing to offer mitochondria replacement should be specifically licensed by the HFEA, and the HFEA should approve each use of mitochondria replacement, at least initially.

The HFEA should commission a further assessment of safety and efficacy once a clinic had submitted an application to carry out one of the techniques, and clinics should ensure that follow-up research took place into the children born as a result. Mitochondria donors should be thought of as tissue donors, and the resulting child should not have an automatic right to identifying information about the donor, although information exchange and contact could be arranged locally by mutual consent.

Catherine Elliott, director of clinical research interests at the Medical Research Council, said, “We consider that there is a compelling clinical need to assess and make these treatments available to women. To do this would require an amendment to UK law, so it has been really important to engage the public in discussion, and the HFEA has conducted a thorough consultation. We recognise that there are those for whom aspects of such treatments raise ethical concerns.

“Parliament can now have a clearer view of what the wider public thinks, and we hope that this will assist it in providing the legal framework needed to help those families affected by these distressing conditions.”


Cite this as: BMJ 2013;346:f1899