6 core challenges that researchers must consider as the race to create models that are ever closer to real human embryos heats up.

Some newly reported clumps of cells growing in lab dishes have been hailed as the closest things to human embryos that scientists have ever made in the lab. These entities are human embryo models — ...

Scientists are exploring ways to mimic the origins of human life without two fundamental components: sperm and egg. They are coaxing clusters of stem cells – programmable cells that can transform into ...

One of the first documents patients sign when starting in vitro fertilization asks them to consider the very end of their treatment: What would they like to do with extra embryos, if they have any?

Scientists have created synthetic blobs that resemble a 14-day-old human embryo for the first time, meaning they can study embryo development beyond a particularly tricky period of pregnancy.

cases and I.V.F. disputes, the frozen embryos vials like these will hold are increasingly caught The Embryo Question is a three-part series about the cluster of cells at the crossroads of science, ...