Although scientists have been able to create and examine human embryos in laboratory settings for decades, they have been limited in their ability to keep them alive outside of a woman's womb, preventing any thorough research into early human development.
Now, researchers say they have discovered a way to keep human embryos alive in the laboratory for one week longer than before, a step they believe will help us better understand human development, miscarriages and birth defects.
"All of this research which we do in the lab should have enormous benefit," said Magdelena Zernicka-Goetz, a professor at the University of Cambridge who helped conduct the research.
Yet for all the scientific promise that these new findings offer, it reignites the debate surrounding the ethics of human embryo experimentation in the laboratory. Furthermore, some are wondering whether or not the rule that limited human embryo research to the first 14 days should be changed.
The new research was published in Nature and Nature Cell Biology today and builds upon Zernicka-Goetz's recent discovery of how to extend the lifespan of mouse embryos in the lab. Using amino acids, hormones and growth factors, Zernicka-Goetz says that embryos can receive the same quality of treatment as they would in the body of the mother.
Zernicka-Goetz's team and a separate team of Rockefeller University researchers then revealed that the same technique worked for human embryos, extending their lifespan in the laboratory for about one week. Even more amazing, the embryos developed in the lab as they did in the womb, organizing themselves into the early stages of complex organs and body structures.
"That was a big eureka moment in the lab," said Ali Brinvalou, an embryologist at Rockefeller University who participated in the research. "All the information necessary and sufficient to have the embryo move forward is already contained within those handful of cells. That was a very big surprise to us and to the field."
Although the findings are exciting, the entire field is divided on the moral implications of such advancements.
"The 14-day rule has kept it pretty limited in terms of what scientists could do," said Daniel Sulmasy, a doctor and bioethicist at the University of Chicago. "Once that goes, then it begins to sort of say: 'It's open season on human embryos. Anything goes.'
"The question has to be: 'Are there any limits to what we will do to human beings in order to gain scientific knowledge?' And then who counts as a human being?"
