British scientists seeking to study miscarriages have applied for a licence to genetically modify human embryos. The application by Kathy Niakan, a stem cell scientist at the Francis Crick Institute in London, was sent to the Human Fertilisation and Embryology Authority (HFEA).

The fertility regulator is expected to grant a licence under existing laws, which allow experiments on embryos as long as they are destroyed within 14 days. Scientists from China became the first anywhere in the world to successfully alter the DNA of human embryos, achieving the feat in April.

Niakan wants to use a gene manipulation technique called Crispr-Cas9 to find out why some women suffer repeated miscarriages. Crispr-Cas9, developed three years ago, allows scientists to make changes to DNA. It is seen to have the potential to transform treatment of genetic disorders by simply correcting faulty genes.

The embryos for the experiments will come from couples with a surplus after fertility treatment and will be destroyed after research, ensuring none grows into a child.

Scientists have in the past successfully edited genetic codes on mice, removing inherited diseases. Even though the process of altering DNA is cheap, easy and effective, many geneticists still believe the procedure is not ready for human embryos. They say the field is moving too fast with the procedure threatening to move from research to clinical use without serious consideration of the implications.

But Niakan has defended her quest saying it is necessary for the advancement of science. "The knowledge we acquire will be very important for understanding how a healthy human embryo develops, and this will inform our understanding of the causes of miscarriage. It is not a slippery slope [towards designer babies] because the UK has very tight regulation in this area," she told the Guardian.