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 ...

To better understand the earliest stages of human growth, researchers can examine donated embryos or human embryonic stem cells, both of which are in limited supply, or address their questions with ...

Researchers that study in vitro fertilization, human development and the diseases that may arise during that time, and miscarriages face a lot of challenges in investigating the biology underlying ...

Researchers have very limited opportunities to study the earliest stages of human development, but a groundbreaking discovery led by a team in Australia will now provide them with a valuable new model ...

Three articles published in Nature describe studies of human prenatal development outside the body. The techniques employed in the studies may illuminate events that unfurl as the beginnings of organs ...

Two groups at Harvard University announced on Tuesday that they have received approval to start human-cloning research aimed at creating lines of embryonic stem cells to study and treat diseases. “We ...

The creation of cellular structures similar to blastocysts has enabled KAUST scientists to build an in vitro model that mimics the earliest moments of human embryogenesis. A blastocyst is the first ...

In two papers published in 2004 and 2005, the South Korean team of now-discredited Woo Suk Hwang reported, first, that it had succeeded in creating cloned human embryos via nuclear transfer and, later ...

The study of early human development has been hindered by technical difficulties and the limited availability of embryonic material for research. The blastocyst is a key developmental stage that ...

New "models" of early human embryos that cannot grow into full human beings provoke ethical questions about whether they are human beings. One ethicist warns that research should be halted out of ...

In some mammals, the timing of the normally continuous embryonic development can be altered to improve the chances of survival for both the embryo and the mother. This mechanism to temporarily slow ...