The Grapevine

'Synthetic Embryos' Could Help Scientists Understand Infertility, Failed Pregnancies

For the first time, scientists created artificial embryos in the laboratory without having to use a sperm and egg. Instead, mouse stem cells were used to create a structure similar to an early embryo i.e. a blastocyst. 

The study titled "Blastocyst-like structures generated solely from stem cells" was published in the journal Nature on May 2.

"What we did is, for the first time, we managed to promote the self-organization of stem cells into a very early embryo in a dish — so everything happened in the lab," said lead author Nicolas Rivron, a biologist, engineer and assistant professor at Maastricht University in the Netherlands.

The breakthrough has been stated to have "opened up the black box of early pregnancy," and has been praised by experts and researchers.

Two types of stem cells were used: Trophoblast stem cells corresponding to the placenta and embryonic stem cells corresponding to the embryo. The researchers found that they self-organized into proto-embryos with the help of molecules. When implanted into the wombs of mice, they were able to initiate pregnancies.

This can help scientists examine the early processes of embryo implantation, something they never had access to before since most women are unaware that they are pregnant at this stage. They are also extremely small, only around the width of a human hair strand. These blastoids are not only easily accessible for study but can be generated in infinite numbers to be tested with new medicines, potentially opening up new opportunities for pharmaceutical research.

The authors add that this is highly important as any abnormalities occurring at the beginning of pregnancy can have major consequences. For one, they can prevent the implantation of the embryo due to age and other factors. Understanding the reasons why can improve assisted reproduction such as In Vitro Fertilization (IVF) treatments which often fail during implantation in the uterus.

Without intervention, the abnormalities can also contribute to the probability of diseases in the later life, including some forms of diabetes or cardiovascular disease. In some of the extreme cases, this can even lead to infertility.

"For the first time, we can study these phenomena in great detail and run drug screens to find medicines that could prevent infertility, find better contraceptives, or limit the appearance of epigenetic marks that appear in the blastocyst and lead to diseases during adult life," said Rivron, adding that lab animals do not have to be used when studying these processes. 

On the topic of animals, he stated he did not yet have answers on whether this process could be replicated in other mammals. If it were feasible, it could prove helpful in saving endangered species. Rivron stated that he and his research team will not create human embryos as he expressed plans to continue using mouse embryos for further studies.