The study of blastoids, a research model of an early embryo derived from stem cells rather than from a father’s sperm or a mother’s egg, offers great hope for researchers investigating why pregnancies ...

Newly created “blastoids” could give scientists a faster and simpler way to research embryonic development than using fertilized human eggs. Made of human stem cells, these blastoids are the most ...

The first steps of human development—those that occur within the first few weeks of pregnancy—remain mysterious in many ways. Within a week of fertilization, human embryos form a blastocyst, which ...