Fetuses can save their mothers' lives

Fetuses can save their mothers' lives

Stem cells from a fetus can travel to the heart and regenerate the muscle, essentially saving a mother’s life.

Adobe Stock

Story by Big Think

In rare cases, a woman’s heart can start to fail in the months before or after giving birth. The all-important muscle weakens as its chambers enlarge, reducing the amount of blood pumped with each beat. Peripartum cardiomyopathy can threaten the lives of both mother and child. Viral illness, nutritional deficiency, the bodily stress of pregnancy, or an abnormal immune response could all play a role, but the causes aren’t concretely known.


If there is a silver lining to peripartum cardiomyopathy, it’s that it is perhaps the most survivable form of heart failure. A remarkable 50% of women recover spontaneously. And there’s an even more remarkable explanation for that glowing statistic: The fetus‘ stem cells migrate to the heart and regenerate the beleaguered muscle. In essence, the developing or recently born child saves its mother’s life.

Saving mama

While this process has not been observed directly in humans, it has been witnessed in mice. In a 2015 study, researchers tracked stem cells from fetal mice as they traveled to mothers’ damaged cardiac cells and integrated themselves into hearts.

Evolutionarily, this function makes sense: It is in the fetus’ best interest that its mother remains healthy.

Scientists also have spotted cells from the fetus within the hearts of human mothers, as well as countless other places inside the body, including the skin, spleen, liver, brain, lung, kidney, thyroid, lymph nodes, salivary glands, gallbladder, and intestine. These cells essentially get everywhere. While most are eliminated by the immune system during pregnancy, some can persist for an incredibly long time — up to three decades after childbirth.

This integration of the fetus’ cells into the mother’s body has been given a name: fetal microchimerism. The process appears to start between the fourth and sixth week of gestation in humans. Scientists are actively trying to suss out its purpose. Fetal stem cells, which can differentiate into all sorts of specialized cells, appear to target areas of injury. So their role in healing seems apparent. Evolutionarily, this function makes sense: It is in the fetus’ best interest that its mother remains healthy.

Sending cells into the mother’s body may also prime her immune system to grow more tolerant of the developing fetus. Successful pregnancy requires that the immune system not see the fetus as an interloper and thus dispatch cells to attack it.

Fetal microchimerism

But fetal microchimerism might not be entirely beneficial. Greater concentrations of the cells have been associated with various autoimmune diseases such as lupus, Sjogren’s syndrome, and even multiple sclerosis. After all, they are foreign cells living in the mother’s body, so it’s possible that they might trigger subtle, yet constant inflammation. Fetal cells also have been linked to cancer, although it isn’t clear whether they abet or hinder the disease.

A team of Spanish scientists summarized the apparent give and take of fetal microchimerism in a 2022 review article. “On the one hand, fetal microchimerism could be a source of progenitor cells with a beneficial effect on the mother’s health by intervening in tissue repair, angiogenesis, or neurogenesis. On the other hand, fetal microchimerism might have a detrimental function by activating the immune response and contributing to autoimmune diseases,” they wrote.

Regardless of a fetus’ cells net effect, their existence alone is intriguing. In a paper published earlier this year, University of London biologist Francisco Úbeda and University of Western Ontario mathematical biologist Geoff Wild noted that these cells might very well persist within mothers for life.

“Therefore, throughout their reproductive lives, mothers accumulate fetal cells from each of their past pregnancies including those resulting in miscarriages. Furthermore, mothers inherit, from their own mothers, a pool of cells contributed by all fetuses carried by their mothers, often referred to as grandmaternal microchimerism.”

So every mother may carry within her literal pieces of her ancestors.

This article originally appeared on Big Think, home of the brightest minds and biggest ideas of all time.

Sign up for Big Think’s newsletter

Ross Pomeroy
Steven Ross Pomeroy is the editor of RealClearScience. As a writer, Ross believes that his greatest assets are his insatiable curiosity and his ceaseless love for learning. Follow him on Twitter
FDA, researchers work to make clinical trials more diverse

The U.S. population is becoming more diverse, but clinical trials don't reflect that, experts say. Some are focusing on recruiting minorities to participate in research.

Adobe stock

Nestled in a predominately Hispanic neighborhood, a new mural outside Guadalupe Centers Middle School in Kansas City, Missouri imparts a powerful message: “Clinical Research Needs Representation.” The colorful portraits painted above those words feature four cancer survivors of different racial and ethnic backgrounds. Two individuals identify as Hispanic, one as African American and another as Native American.

One of the patients depicted in the mural is Kim Jones, a 51-year-old African American breast cancer survivor since 2012. She advocated for an African American friend who participated in several clinical trials for ovarian cancer. Her friend was diagnosed in an advanced stage at age 26 but lived nine more years, thanks to the trials testing new therapeutics. “They are definitely giving people a longer, extended life and a better quality of life,” said Jones, who owns a nail salon. And that’s the message the mural aims to send to the community: Clinical trials need diverse participants.

Keep Reading Keep Reading
Susan Kreimer
Susan Kreimer is a New York-based freelance journalist who has followed the landscape of health care since the late 1990s, initially as a staff reporter for major daily newspapers. She writes about breakthrough studies, personal health, and the business of clinical practice. Raised in the Chicago area, she holds a B.A. in Journalism/Mass Communication and French, with minors in German and Russian, from the University of Iowa and an M.S. from the Columbia University Graduate School of Journalism.
Send in the Robots: A Look into the Future of Firefighting

Drones are just one of several new technologies that are rising to the challenge of more frequent wildfires.

Courtesy of USDA Forest Service

April in Paris stood still. Flames engulfed the beloved Notre Dame Cathedral as the world watched, horrified, in 2019. The worst looked inevitable when firefighters were forced to retreat from the out-of-control fire.

But the Paris Fire Brigade had an ace up their sleeve: Colossus, a firefighting robot. The seemingly indestructible tank-like machine ripped through the blaze with its motorized water cannon. It was able to put out flames in places that would have been deadly for firefighters.

Firefighting is entering a new era, driven by necessity. Conventional methods of managing fires have been no match for the fiercer, more expansive fires being triggered by climate change, urban sprawl, and susceptible wooded areas.

Keep Reading Keep Reading
Eve Glicksman
Eve Glicksman is a freelance writer and editor in Silver Spring, MD. She writes for multiple media outlets and associations on health care, trends, culture, psychology, lifestyle, and travel. To see her work in the Washington Post, WebMD, and U.S. News & World Report, visit eveglicksman.com.