Secrecy surrounding births may mean new IVF procedures have failed
News that Britain’s first “threeparent babies” have been born is a cause for celebration, but it also raises serious questions about the technique, and the secrecy surrounding the births.
The procedure, pioneered in the UK, essentially replaces the power-source (mitochondria) of an egg, using donor “battery” DNA from a second female.
It enables babies to be born free from debilitating conditions such as muscular dystrophy, offering a lifeline to women who have avoided having children for fear of passing on devastating diseases.
The Newcastle Fertility Centre, part of Newcastle University, is the only clinic in Britain with a licence to attempt the technique. Yet news that the first babies had been born did not come from them, but via a Freedom of Information request submitted by The Guardian newspaper.
Requests for more details have met a wall of silence and no information about the births has been published in scientific journals.
The Newcastle team are clearly concerned about preserving the anonymity of the families involved, and they may also be awaiting a longerterm follow-up before announcing their success. But it could also mean that the procedures have failed.
In recent years worrying questions have been raised about the safety of the technique, which has been carried out in a number of other countries.
Several babies have displayed what scientists call “reversion” where the proportion of the disease-causing mitochondria from the mother increases alarmingly over time, sometimes to as much as 72 per cent.
Some studies suggest that around one in five babies born using the three-parent technique would eventually inherit enough defective mitochondria to place them at great risk of potentially fatal conditions.
Scientists exploring the treatment in Belgium and Ukraine have already paused the procedure, over fears that the risks far outweigh the benefits, with couples advised to consider donor eggs or adoption instead.
In February, researchers including Oxford University published a study which had used the technique to try to improve IVF success rates. Six healthy babies were born, but one displayed reversion of 50 per cent back to the birth mother’s DNA.
In that case, none of the mothers was carrying defective mitochondrial DNA but, at the time, the scientists warned that if they had been, it would have placed the baby at great risk.
Oxford researchers said the sample size was too small to predict how many babies might be affected by reversion, but said it could be far higher than the one in six cases they saw.
Even when Newcastle University scientists undertook the first trials on human embryos in 2016, around 4 per cent of mutated DNA carried over, and the experts warned they could not guarantee that the procedure would prevent disease. In one instance mutated DNA which had carried over was found to increase over time until it reached disease-causing levels.
The technique has always been controversial. Critics have argued that the resulting babies have the genetic make-up of three people, which could have unknown physical or psychological implications for the child and its descendants.
The Government was forced to undertake a lengthy public consultation in 2015 before finally changing the law to allow doctors to proceed on a case-by-case basis.
At the time, experts warned that babies could be at greater risk of cancer and premature ageing and would need to be monitored all their lives. It is also possible that their own children would need monitoring, because the modification would pass through the germ line.
Several scientists warned that it was unknown how mitochondria interacted with nuclear DNA. Christian groups argued that it would open the door to “designer babies” and said the procedure crossed an ethical line.
Some even queried whether it was needed at all. While one in 200 children is born each year with some level of mitochondrial disorder, only one in 10,000 is severely affected, raising questions as to whether such a major intervention was justified.
The first baby was born from the technique in Mexico in 2016, and there have been published reports of around a dozen others around the world.
Newcastle scientists were granted a licence in March 2017, yet six years on we have seen no evidence it has proved effective. On the contrary, more and more evidence is emerging of the risk.
‘Requests for more details have met a wall of silence and no information has been published in journals’