As you age, your fertility slowly declines. By freezing eggs or embryos when you’re young (usually under the age of 40), you can preserve your eggs’ health and, through in vitro fertilization (IVF), ...

Lab-grown structures with the potential to develop into fetuses should be defined — and regulated — as embryos, some researchers say. It is time for a redefinition of the human embryo, a team of ...

The world has now learned of a surprising scientific advance: so-called “synthetic embryos.” Their arrival promises to reveal to medicine previously hidden glimpses into problems of early pregnancy.

Synthetic human embryos — also called embryoid bodies, embryo-like structures or embryo models — mimic the development of “natural human embryos,” those created by fertilization. Synthetic human ...

With embryolike constructs built entirely from stem cells, researchers can revolutionize our understanding of development. But how close to an embryo is too close? In April, researchers in China ...

The majority of fertilized eggs die and are resorbed into the body. ZEISS Microscopy/Flickr, CC BY-SA As an evolutionary biologist whose career has focused on how embryos develop in a wide variety of ...

Frozen embryos are filling storage banks around the world. It's a struggle to know what to do with them. Lisa Holligan already had two children when she decided to try for another baby. Her first two ...

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, ...