The UK could have its first 'three-parent baby' as soon as 2018.
Fertility regulators have given the first British licence to create embryos from two women and one man to doctors in Newcastle.
So is this as dodgy as it sounds?
Well, the intention of the procedure is good. The aim is to overcome hereditary mitochondrial diseases passed down through genes which leave people without enough energy to keep their own heart beating.
The team in Newcastle expects to be able to help around 25 couples every year who might otherwise have lost their children.
How does that actually work?
The disease is caused by faulty mitochondria, tiny parts of each cell that convert food to energy. The defect is passed down through the mother's DNA .
So the procedure works by taking the unhealthy fertilised embryo from the two parents and removing the nucleus. This contains all the key information that defines our physical traits. That nucleus is then inserted into a donor embryo which does not have the unhealthy mitochondria.
It sounds great. What is the problem?
Well a number of ethicists, including some Christians, say the procedure is problematic because it involves mixing the DNA of three different people.
Opponents also say the long-term consequences of mixing DNA are unknown and could cause harmful effects in two or three generations time which we don't know about yet.
Mark Bhagwandin, from Life charity, said: 'There is nothing cautious about the approval of a licence which will result in the uncertain and potentially dangerous genetic modification of human beings.
'It is at the very least reckless and irresponsible given that we have absolutely no idea what the long term consequences are to us interfering with the human genome.'
Are there any other concerns?
Others have said the procedure is 'playing at God' and opens the door to designer babies.
Al Mohler, president of the Southern Baptist Theological Seminary, said it is 'the opening of a door, the beginning of an experiment that cannot possibly stop here'.
Although he admits the primary aim is to cure a disease, he raises the idea of it being a slippery slope and says it is one step that will be used to justify the next.
'It opens the door inevitably to designer babies', 'redefining what it means to be human,' he says in a podcast.
'It appears to be a very small issue, but it opens a very big door.'
Are all Christians opposed to it?
No not at all. The Church of England is sitting on the fence and says it doesn't outright disagree with the procedure but wants more research on the impacts as well as further debate on the ethics of the issue.
But Professor John Bryant, a Christian biosciences expert at the University of Exeter, is much more forthright in his approval. He told Christian Today when the legislation was first approved: 'The idea that this puts us on a slippery slope to designer babies is nonsense.
'The technology for doing that involves altering nuclear genes – ie. the main set of genes – and that technology has been available for over 25 years.
'Nobody has suggested that it should be legal to use it with human embryos even though it is very widely used with other mammals, especially mice for use in medical research.'
