New study In the early stages of fetal development, it provides insight into why many pregnancies end in miscarriage.

Body axis “head – tail”

Concretely, scientists at the University of Cambridge have identified key molecular events that occur during the second week of pregnancy, one of the most critical stages of embryonic development.

Between seven and fourteen days after the egg is fertilized, a group of cells outside the embryo, called the “hypoblast,” begins to develop the “head-tail” axis of the embryo. This step, which determines the location of the future baby’s head, begins the formation of the human body.

“One of the main reasons for early pregnancy failure”

Failure to thrive during this period is one of the main causes of early pregnancy failure in patients undergoing adjuvant contraceptive treatments. The scientists report, published in the journal Nature.

This finding is significant because, for obvious ethical reasons, research on human embryos is restricted by law. The credit goes to Professor Magdalena Zernicka-Goetz, who in 2016 devised a technique for developing human embryos outside the body, allowing them to be studied up to the 14th day of development.

“We revealed patterns of gene expression in the developing embryo after implantation in the womb, which reflect the multiple exchanges between different cell types as the embryo develops to these early stages,” Concluding Zernica Goetz.