Scientists Discover What Makes Human Embryo Attach to Uterus
A UCSF-led research team has identified the first molecular step that allows a week-old human embryo to attach to the uterus. The finding is expected to provide a new tool to diagnose and treat infertility and early pregnancy loss, the scientists report.
The researchers found convincing evidence that a molecular sticking process stops the embryo's journey along the uterine wall and starts attaching it to the wall -- the first stage of implantation. Failure of the embryo to implant causes about three-fourths of lost pregnancies.
The research is published in the January 17 issue of the journal Science. A perspective article on the research also appears in the issue.
The team found that about six days after fertilization, molecules on the embryo' s surface interact with molecules on the mother's uterine wall to create the sticky environment - the same combination of molecules known to stop the movement of disease-fighting leukocytes migrating through blood vessels, and allow them to attach to the blood vessel walls in areas of inflammation.