The survival of a sheep 21 days outside the maternal belly that opens the door to saving extreme preemies

BarcelonaHer name is Gaia, she is already over a year old and is a normal, everyday sheep, which makes her extraordinary due to the way she came into the world. When she was still a fetus, they removed her from her mother's womb, even though she was not developed enough to survive outside and her organs were not mature enough to perform basic functions like breathing or digesting. The people who did it, however, had a plan: to deceive nature.

Researchers from BCNatal, a center affiliated with Hospital Clínic, Hospital Sant Joan de Déu, and the University of Barcelona, artificially recreated the conditions of the maternal uterus so that Gaia could continue to develop. In fact, the specimen spent 10 days inside Europe's first artificial placenta and 13 months later is indistinguishable from any other sheep. Now Catalan scientists have managed to extend this period to 21 days with another sheep; a scientific milestone that has only been achieved in the United States and Barcelona and which paves the way for finding a solution for extremely premature babies in the future.

Once it has been demonstrated that the project is scientifically viable, the BCNatal team is working to test it on humans. The aim is to reduce the severe sequelae that affect most extremely premature newborns, i.e., those born at six months or less. These babies have significant neurological, bronchopulmonary, intestinal, and cardiovascular complications that put their lives at risk, and this project seeks to offer a solution to guarantee their survival, which is currently low or with lifelong severe sequelae.

"When we go below six months, we cannot guarantee a 90% survival rate and a low risk of sequelae," explained the director of BCNatal, Eduard Gratacós. In the presentation of the project this Friday, the expert compared the 21-day milestone to the first heart transplant, which was performed for the first time 60 years ago and is now a normal procedure that saves thousands of lives each year.

After five years and 7.65 million euros invested by La Caixa Foundation, a technological improvement has been achieved that is significant enough to reach 21 days of survival and achieve a successful neonatal transition. This transition simulates the preliminary steps for its future application in humans, that is, the transfer from the artificial placenta to a conventional incubator when the organs have already matured enough. It is a process similar to the "birth of the fetus", where it passes from this environment that simulates the artificially recreated mother's womb and begins to use its lungs like any newborn.

Another of the major advances achieved so far has been the improvement of the extracorporeal circulation system. It consists of a membrane and a system of parts that have been specifically designed to facilitate blood circulation and oxygenation, simulating what naturally occurs through the maternal placenta and umbilical cord.

Bioethics Committee

However, there is a long way to go before the first human trials can be conducted. Since 2021, the project has had its own committee for ethical, social, and safety aspects – which includes representatives of newborn families – for the development of the trial. The ethical aspects for this technology to eventually be used in humans are being worked on by the Borja Institute of Bioethics.

The proponents of this artificial placenta, however, assure that the project has been analyzed and favorably evaluated twice by a panel of internationally renowned experts in fetal and neonatal medicine from five countries. This is an example of the multiplying effect of collaboration between public institutions and philanthropy in biomedical research and innovation.