In news that may be awe-inspiring to some and shocking to others, scientists for the first time have been able to grow an embryo for 13 days beyond fertilization. What makes this groundbreaking is that the researchers from the University of Cambridge in the U.K. blew away the previous record (nine days) by almost 50 percent. Pretty amazing.
Here is a summary of what the group accomplished.
When an embryo has implanted itself within the uterus it is a major developmental step.
“Implantation is a milestone in human development as it is from this stage onward that they embryo really begins to take shape and the overall body plan are decided," said professor Magdalena Zernicka-Goetz, one of the lead authors of the study. "But until now, it has been impossible to study this in human embryos. This new technique provides us with a unique opportunity to get a deeper understanding of our own development during these crucial stages and help us understand what happens, for example, during miscarriage.”
The embryos were donated for research purposes from women who had undergone in vitro fertilization. Then in the lab, these cells were grown in a modified nutrient broth, called a culture medium. The change in the broth, which was based on earlier work on mouse embryos, involved the use of different hormones and nutrients.
Some background: Immediately after fertilization embryos undergo a series of cell divisions until the become what is called a morula — a solid ball of cells— around the 16 cell stage. Then it continues to divide for an addition three-and-a-half to four days, at which point it has developed into a hollow ball of cells, known as a blastocyst. At this stage, the embryo has not yet implanted itself in the uterus. The entire process of implantation must be completed 12 days following fertilization.
During this time, the embryo is at highest risk. It is the do-or-die phase. If implantation does not occur successfully, the embryo will die. This is very common — so much so that potential mothers do not even realize that anything took place. Current estimates are about half of embryos do not survive past this stage.
Understanding the complex processes that are taking place during this crucial time will inevitably help so many couples trying to achieve a successful pregnancy. Now, this study can take place in a cell culture. Prior to this, the formation of embryos could not be thoroughly studied, since they were in the womb.
This is a tremendous advance for modern science. Although, ethical concerns and controversy will always be present, it would seem that the benefits of understanding the specific biochemical changes taking place in the developing embryo will ultimately yield a gold mine of knowledge – and hope for the many couples trying to conceive.