The genetic modification of human embryos remains a controversial issue, but a British scientist is hoping to become the first in the U.K. to gain approval to perform the process. It could be used to reduce miscarriages and increase the success rate of IVF.

Many of the genes which become active in the week after fertilisation are unique to humans, so they cannot be studied in animal experiments. "The only way we can understand human biology at this early stage is by further studying human embryos directly," Dr Niakan said. Such experiments are legal in the UK as long as the modified embryos are not implanted into people.

More information about this study here