The American Society for Reproductive Medicine, one of the largest fertility organizations in the United States, offers non-legally enforceable recommended guidelines encouraging fertility clinics to ...

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 ...

Monozygotic twinning itself after elective single embryo transfer is uncommon, occurring in no more than roughly 3% of cases. Conjoined twins are far rarer still, with fewer than 20 cases reported ...

Scientists have developed an experimental way to study how human embryos implant in a uterus, which may provide new insights ...

A doctor claims to have cloned human embryos and implanted them in women. April 23, 2009— -- A controversial fertility doctor claims to have cloned human embryos and implanted them into four ...

Our ancient past isn't always buried history. When it comes to our DNA, nearly 9% of the human genome is made up of leftover genetic material from ancient viruses (called endogenous retroviruses or ...

A lot happens in the first month of human embryo development as a single cell morphs into multitudes. Yet despite its significance, this period is basically a “black box” to researchers, says stem ...

A team of scientists has just gotten a closer peek into one of the earliest and most fundamental steps of creating a human life. Research out today highlights how they captured—for the first ...