Last year scientist Jiankui He caused controversy when he revealed he used CRISPR to edit human embryos, resulting in the birth of twins Lulu and Nana. It's now been reported a second woman is pregnant with a gene-edited baby in China.
There are numerous and complicated medical concerns with gene-editing humans, but what of the philosophical and ethical issues?
Professor of Philosophy at La Trobe University, Janna Thompson, has written a piece about the social problems designer babies could cause in The Conversation, she explains her concerns.
A human embryo, here seen in its eight-cell stage, doubles its number of cells at each division. Photo: Wikimedia commons
