Ava Answers is a column exploring the science of sex by Ava Mainieri, a PhD student studying women’s health at Harvard University.
We all know that crazy ex-girlfriend. She’s the one used as a punchline at a party because she sent a string of twenty unanswered texts. She’s the one who showed up at his house, a mess of tears, and forced him to rehash the whole breakup. She’s one who proclaims on all social media platforms how happy she is and then two days later calls him to re-profess her love. I don’t need more examples to demonstrate that we live in a society that affirms “bitches be cray.”
If you have ever found yourself obsessing over a breakup, take note: scientists have evidence that your ex-boyfriend can remain part of you long after you toss his toothbrush from your bathroom. This is not some love metaphor, but a biological fact.
During pregnancy, cells from the embryo push their way through the placenta and travel to the mother’s uterus, breast, and brain. As the majority of pregnancies are silent and spontaneous miscarriages, women may have multiple men taking residence in their bodies. Don’t beat yourself up for obsessing over your ex long after the breakup — he’s literally in your brain.
Most women don’t even originally know they’re pregnant. The American College of Obstetricians and Gynecologists speculates that approximately 60% of miscarriages occur within the first three months of pregnancy, and that the majority of women don’t even know it is happening. They might experience a single missed period or a heavier than usual blood flow. These embryos overwhelmingly have an abnormal amount of chromosomes (the instruction manual needed to form a baby) — a problem that happens just by chance, not because of anything the mother did. But even within those first few weeks, tiny parts from the growing ball of cells (a fetus) can escape the uterus and spread through the mother’s body. Scientists call the phenomenon fetal microchimerism, after the Greek mythological animal made up of the head of a goat, body of a lion, and tail of a snake.
These tiny invaders don’t just passively enter the mother’s body. A recent experiment found that fetal cells can be identified in a woman’s body as early four to five weeks into pregnancy. Then, the majority actively migrates to the uterus, breasts, and brain. Though many disappear after a few years, some can stick around in the body up to 27 years after pregnancy. A 2012 study dissected brains of around 60 deceased older women and found Y chromosomes (meaning they came from a male pregnancy) in 63% of them. However, these cells were rare — only making up around 1 in every 1000 cells. But fetal cells that had trekked to the brain, developed into healthy brain tissue and the few that traveled to the heart also became heart tissue.
But it is still unclear if these cells act as a mother’s tiny helper. Fetal cells have been documented to migrate to damaged organs in a woman where they transform into other tissue cells; hinting that their goal may be to mend and repair. Some of these cells are stem cells, which can turn into many types of different tissues. They have been found in wounds, like caesarian scars and thyroid tumors, which hint at their active assistance in healing. Despite that, other researchers argue these foreign bodies are causing more harm than good. They may contribute to autoimmune disorders and inflammatory responses like Graves’ disease and Multiple Sclerosis (MS). Fetal cells may be the culprit to blame in part for higher rates of autoimmunity in women. For example, we have three times higher rates of rheumatoid arthritis than men.
From an evolutionary perspective, it is in the interest of the father to try and manipulate the mother. Because the embryo contains genetic material from both parents, the fetal cells that sneak into the mother’s body get half of their instructions from their father. Each baby’s chance of surviving is directly tied to the amount of resources like blood, sugar, and milk it takes from its mother. Because the man does not know if this will be his only child with a woman, he wants his offspring to receive as much nutrition as possible. Therfore, it’s possible fetal cells could be manipulating their mother to drive up blood flow, milk production, and attention.
Work in my own lab raises the possibility of an even more alluring prospect: fetal cells in the brain may be influencing a woman’s emotions and behavior. Because they are primarily found in the hippocampus of a woman’s brain, we speculate that they might not only influence bonding between a mother and her child, but possibly between a woman and her mate. You shouldn’t really fault yourself for monitoring your ex’s activity on Instagram — it could be his genetic material behind your obsession.
Whether or not the greater scientific community agrees with this hypothesis is moot. What is important is that scientists are finally giving heartbreak and women’s health the attention it deserves. As late as the 1980s, whenever someone did not want to deal with a woman’s emotions or was generally alarmed with her behavior, she was taken to a doctor and diagnosed with hysteria. This “syndrome” acted as a sweeping label for all who felt enraged, depressed, too aroused, not aroused enough, and a slew of other ailments thought to be caused by just being a woman. The word hysteria comes from the Greek ‘hystera’ which means uterus, so the condition of hysteria literally meant the misfortune of being a woman.
The peril with feeling crazy is that it discredits us — when we are in an argument, vying for a promotion, or protesting a Supreme Court Justice nomination. It causes us to explain away our emotions instead of scrutinizing them. In scenarios where our voice needs to be heard, it can put the blame on us rather than someone else’s arguable behavior.
Not only is pathologizing women’s emotions demeaning, but it is also scientifically incorrect.
Second photo by Antonia Adomako.Â