One of the most miraculous medical discoveries in recent years reveals a powerful secret shared between mother and child. During a heart attack, a pregnant woman’s fetus can send stem cells to help repair her heart, a hidden life-saving connection that science is only beginning to understand. Illustration by the author. © 2025 Mariah
Even before birth, a baby can start leaving meaningful traces.. Scientists have observed a phenomenon known as fetomaternal microchimerism, where fetal cells cross into the mother’s bloodstream during pregnancy. Some of these cells don’t just float around. They can settle in places that are damaged, including the heart. And in some cases, they might play a role in repair.
These cells have been found in organs like the liver, kidney, thyroid… and the heart. They can take on the kinds of cells the organ seems to need. Early studies, in animals and in people, hint that they could help the heart recover after stress or injury. Nobody knows how much they contribute, or in what ways, is still being studied.
It’s a reminder of how connected mother and child are. Life supporting life, in ways you can’t always see. And maybe, quietly, the baby is giving something back long before it even takes its first breath.
References:
Chaudhry, H., et al. (2011). Fetal cells from placenta may help maternal heart recover from injury. Mount Sinai Health System. https://www.mountsinai.org/about/newsroom/2011/fetal-cells-from-placenta-may-help-maternal-heart-recover-from-injury
Kara, R. J., Bolli, P., Karakikes, I., Matsunaga, I., Tripodi, J., Tanweer, O., Altman, P., Shachter, N. S., Nakano, A., Najfeld, V., & Chaudhry, H. W. (2012). Fetal cells traffic to injured maternal myocardium and undergo cardiac differentiation. Circulation Research, 110(1), 82–93. https://doi.org/10.1161/CIRCRESAHA.111.249037
Lintao, R. C. V., Kammala, A. K., Radnaa, E., & Menon, R. (2023). Presence of fetal microchimerisms in the heart and effect on cardiac repair. Frontiers in Cell and Developmental Biology, 12, 11350564. https://doi.org/10.3389/fcell.2024.1390533
Pritchard, S., Bianchi, D. W., & Mount Sinai School of Medicine. (2012). Fetal cell microchimerism in the maternal heart: Baby gives back. Circulation Research, 110(1), 3–5. https://doi.org/10.1161/CIRCRESAHA.111.260299
