![](https://www.popsci.com/wp-content/uploads/2019/03/18/YHQGUHOK5K2ATWAXIHF2KS5BQ4.jpg?quality=85&w=976)
![](https://www.popsci.com/wp-content/uploads/2019/03/18/YHQGUHOK5K2ATWAXIHF2KS5BQ4.jpg?quality=85&w=976)
Researchers from the Karolinska Institutet in Sweden will be coordinating a study in which 30 fetuses will be injected with stem cells to treat a severe genetic condition, according to a press release. This is the first time a trial will test a treatment designated for unborn babies, the BBC reports.
The stem cells are specially designed to treat brittle bone disease, which is incurable and affects up to 50,000 people in the U.S. alone. People with brittle bone disease have several genetic mutations that prevent the body from making collagen, which it needs for bones to grow strong. Babies born with the disease are often born with several broken bones, which can affect many of the body’s other functions. Though many with milder forms of the disease survive, almost all babies with the severe form die shortly after birth due to respiratory problems.
Now researchers have developed a special kind of stem cell that can treat brittle bone disease by producing bone-strengthening collagen. They’ve tested the stem cell on older children and on fetal mice, all of which have shown promising results. They predict that, should the treatment be given earlier in life, it could be even more effective.
For the past few years, researchers have hypothesized that in-utero stem cell treatments would be possible. Treatments that have shown good results in animal tests didn’t work in humans because the mother’s immune system was killing the stem cells before they reached the fetus, and though researchers had a few ideas for how to work around this issue, they had not yet figured out how to do it, according to a 2011 article from MIT Tech Review.
In the Karolinska Institutet trial, half of the babies will receive stem cells before they are born, while the other half will receive them afterwards. Following the births, groups of babies will also receive new treatments every six months for two years. It’s not clear from the press release if the researchers have found a way to prevent the mother’s immune system from attacking the cells for those babies treated in utero. But if the trial is successful, the method might improve the lives of millions of children born with dozens of genetic conditions.