How Your Baby’s Cells Can Heal You During and After Pregnancy (And Why It Matters)

The Science and Benefits of Fetomaternal Microchimerism

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Did you know that when you are pregnant, your baby’s cells can cross the placenta and enter your body, where they can become part of your tissues and organs? This phenomenon is called fetomaternal microchimerism, and it has some amazing implications for your health and well-being.

What is fetomaternal microchimerism?

Fetomaternal microchimerism is defined as the persistence of fetal cells in the mother for decades after pregnancy without any apparent rejection. Fetal microchimeric cells (fmcs) engraft the maternal bone marrow and are able to migrate through the circulation and to reach tissues.

Scientists have been aware of fetomaternal microchimerism’s existence (in broad terms) for decades. A 1996 study found that in humans, genetically distinct cells from a male fetus persisted in the mother’s body as long as 27 years after birth. Later research has demonstrated that these fetal cells can be found in multiple organs in both human and laboratory mice mothers, such as blood, bone marrow, skin and liver.

Fetomaternal microchimerism can get even more complex when a mother has multiple pregnancies. The mother’s body accumulates cells from each baby — and potentially functions as a reservoir, transferring cells from the older sibling into the younger one and forming more elaborate microchimeras. The presence of fetal cells in the mother’s body could even regulate how soon she can get pregnant again.

How do fetal cells help the mother?

Fetal cells are like stem cells, which means they can grow into many kinds of tissue. Once in the mother’s blood, these cells use chemical cues from neighboring cells to grow into the same stuff as the surrounding tissue. This means that they can potentially repair or regenerate damaged organs in the mother.

A 2015 study published in the journal Circulation Research addressed the issue of fetal stem cells actually healing maternal organs. In this study, researchers mated female mice with transgenic male mice that were tagged with a fluorescent protein that allowed the researchers to trace…