Motherhood Changes You Forever, Literally!
There are innumerable maxims in our culture to describe the extraordinary experience of motherhood. We talk about how our children become a part of us, so much so that we feel their pain and their joy. We are aware that motherhood changes you immeasurably. And, our babies remain in our hearts forever, even after they’re all grown up.
The magic of motherhood is almost overwhelming at times. We feel it very physically – both when things are wonderful and when things are challenging – and we defer to these common sayings to try to explain this totally unique life experience.
As it turns out, these sayings are actually backed up by biology.
Fetal-maternal microchimerism is the exchange of cells between mom and baby during pregnancy. The result of this cell-exchange process is that both mom and baby become human chimeras – they both retain some of each other’s cells for a long time after birth. Mom and baby have different genes, yet they literally become part of one another during pregnancy.
How Does Microchimerism Happen?
Since mom and baby are genetically distinct, the fetus and placenta are essentially foreign entities inside mom’s body. A pregnant woman is technically a human chimera because she is a single body containing two unique sets of genes: her own and her baby’s.
One of the placenta’s jobs is to tap into mom’s arteries to control blood flow and ensure the fetus has access to nutrients. However, the placenta works both ways, also depositing fetal material into mom’s blood stream.
This fetal material includes fetal cells, which, like stem cells, are pluripotent. This means that they can turn into many different types of tissue by using chemical cues to replicate the cells closest to them – wherever in the body they end up.
The result of this is that a woman who has carried a baby can live for decades after giving birth with cells inside her organs that contain different genes from her own.
What Do Fetal Cells Do?
Mom’s immune system will flush out the fetal material that sticks around in the bloodstream, but the fetal cells that enter mom’s tissue and organs change form and go undetected by the immune system, so they can remain in the body for a long time.
For example, fetal cells can enter the liver and become liver cells, or they might go into the heart and become muscle cells, and they can even enter the brain and become neurons.
Scientists are currently studying how the fetal cells that have integrated with mom’s tissue and organs work.
So far, there are signs that fetal cells might be more prevalent in breast tissue, where they have two possible functions: signaling the production of milk and encouraging healthy lactation, and killing breast cancer cells.
Fetal cells have also been found in C-section scars, producing collagen to help the healing process, and they have been linked to a reduced risk of rheumatoid arthritis.
On the flipside, depending on baby’s genes, the fetal cells could trigger autoimmune diseases. They have also been linked to preeclampsia and there are questions surrounding their effect on how quickly mom is able to become pregnant again.
Generally though, scientists seem to agree that the fresh young fetal cells probably do more good than harm in mom’s body. The next phase of research involves using modern sequencing technology to locate these cells and observe the way they interact with their surroundings.
Motherhood Really Does Change You
So, the next time someone rolls their eyes at you when you try to tell them that motherhood is life changing or that your baby is part of you: show them the research! You are now living with cells that are genetically not your own. If that’s not life-changing, what is?
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