WASHINGTON — For the first time, scientists have used human cells to make structures that mimic the earliest stages of development, which they say will pave the way for more research without running ...

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 ...

Sperm may lose their ability to navigate in microgravity, raising new questions about whether human reproduction is possible ...

New study finds microgravity disrupts sperm and embryo development, raising concerns about human reproduction in space.

Many state legislatures are seriously considering human embryos at the earliest stages of development for legal personhood. Total abortion bans that consider humans to have full rights from the moment ...

Their discoveries show how both resilient and fragile life can be in the absence of gravity. In low gravity, sperm lose their ...

Single-embryo transfer has been recommended to reduce the incidence of multiple gestations when in vitro fertilization is performed in women under 36 years of age. We designed a prospective, ...