‘Complete’ models of human embryos created from stem cells in lab

Tiny structures are not identical to human embryos, but could have various uses in medical research

Researchers have created complete" models of human embryos from stem cells in the lab and grown them outside the womb, in work that paves the way for advances in fertility, pharmaceutical testing and transplants.

The tiny balls of tissue were made by combining stem cells that arranged themselves into structures that mimic the 3D organisation of all the known features found in human embryos from one to two weeks old.