Developing Views

Groundbreaking images show an implanting embryo

- By Humberto Basilio

RESEARCHERS HAVE CAPTURED the very first real-time, three-dimensional images and videos of a human embryo implanting into synthetic uterine tissue—revealing a key stage in reproduction. The resulting footage, which shows in vivid detail how embryos push and pull to anchor themselves in the uterus, could lead to improvements for in vitro fertilization techniques, the scientists say.

“This will allow us to develop treatments specifically targeting implantation, which is the biggest roadblock in human reproduction,” says Samuel Ojosnegros, a bioengineer at the Barcelona Institute of Science and Technology and a coauthor of the new study in Science Advances.

A few days after an embryo is fertilized artificially, fertility doctors must implant it into the body so it can continue to grow. “What happens between the transfer and the first ultrasound weeks later is a black box,” says Ojosnegros, who is also co-founder of biotech company Serabiotics. Implantation failure is one of the main causes of infertility—up to 60 percent of miscarriages occur during this process.

The first successful cultures of human embryos beyond the moment of implantation were demonstrated in laboratory petri dishes in 2016, but Ojosnegros and his colleagues wanted to see what this process would look like in 3D tissue that was more similar to that of the uterus.