Study Suggests That Women Absorb DNA From Every Man They've Ever Slept With

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Study Suggests That Women Absorb DNA From Every Man They've Ever Had Sex With

A few sites have published scary articles claiming women carry the DNA of every man they have had sex with. But is there any scientific studies to prove it?

The science on this topic is not completely out —just yet, but a study originally conducted on mice DNA and later performed on the brains of deceased female subjects hints that women may carry traces of microchimerism—  not only from giving birth to a male fetus—  but from men they have had sex with.

Yes, male DNA, aka the Y chromosome entered into a woman's body from a man's sperm is thought to have been discovered in the brains of female test subjects.

Sounds, gross, right? Shudder!

Is it possible that sexually transmitted diseases aren't the only thing women need to worry about getting from a male sexual partner?

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Most women can't stand the idea of being around an ex, let alone want to imagine that there might be a lingering Y chromosome of his floating around her own gene pool.

If this science proves to be true, breaking up being hard to do will go up a level.

If you're wondering how did scientists concluded that male DNA is absorbed into a woman's body, here are 6 things to know about studies on microchimerism:

1. What is microchimerism?

"Microchimerism is defined as the presence of two genetically distinct cell populations in the same individual." 

Stated simply, DNA transfer from one person to another, is nothing new. Mothers transfer their DNA cells to their fetus during pregnancy.

It can also happen during blood transfusions and organ transplants. 

2. In 2011, the first study to recognize that there was a connection between a baby's gender, complications in pregnancy and microchimerism. 

The study was being done to find out why there were more birth complications in women when a male fetus was present.

The study, after evaluating the female subjects noticed that there was male DNA in their brains from over a decade earlier.

Interestingly, women who had given birth to a male child developed an H-Y antigen, which happens when a female is exposed to the Y chromosome of a male.

So, when the same women got pregnant with another male baby, the H-Y antigen could cause an allergic reaction and her body would become at risk to miscarry.

This did not happen in women pregnant with a female fetus. And, if a woman had a short period of time between sexual partners, her risk increased.

A woman's exposure to the first male's sperm and DNA increased the odds of problems during pregnancy with when impregnated by another new male partner

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3. Women with autoimmune disorders including HIV or AIDS were thought to be most at risk, but a second study says, maybe not.

In 2012, scientists performed another study on Mc, "Male Microchimerism in the Human Female Brain". But in this study, none of the women had an autoimmune disorder. 

Some of the women had given birth to male children, but some of the women had not. 

They found traces of male DNA in most all female brains— those who were mothers, and those who were never known to have been pregnant. 

"Also unique to our study are the findings that male Mc in the human female brain is relatively frequent (positive in 63% of subjects) and distributed in multiple brain regions, and is potentially persistent across the human lifespan (the oldest female in whom male DNA was detected in the brain was 94 years)." 

4. In 2015, another study on microchimerism in mothers who only birthed daughters discovered male DNA in their bodies, too. 

"We speculate that sexual intercourse may be important but other sources of male cells likely exist in young girls."

Other possible reasons for the positive test result could have been a pregnancy that miscarried or even prior blood transfusions.  

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5. Girls with older brothers have tested positive for microchimerism, but so did younger ones. 

"There was a tendency that girls were more likely to test positive for male microchimerism if their mothers previously had received transfusion, had given birth to a son or had had a spontaneous abortion. Furthermore, the oldest girls were more likely to test positive for male microchimerism."

So, there are a few ways that a person could get a male chromosome into their body. So, just like women need to protect themselves against STDs, this might give another reason to use a condom. 

6. How does microchimerism threaten women's health, if they were to test positive?

A 2015 study revealed that women who test positive for Mc or microchimerism are at greater risk for complications in pregnancy when giving birth to male children, especially if those male children have different fathers. 

"The current state of literature on fetal microchimerism and maternal health presents a paradoxical picture, with some papers concluding that fetal microchimerism contributes to poor health outcomes in certain cases and improved outcomes in others. For example, fetal cells have been proposed to play a role in maternal wound healing [16, 17], but have also been associated with pregnancy complications including, atypical fetal karyotype (e.g. Down Syndrome), pre-eclampsia, miscarriage, and premature birth [18-22]. Fetal cells have also been identified at multiple tumor sites, including breast, cervical, and thyroid cancers, as well as melanomas". 

The good news is that the science on this theory is incomplete at this time and more research is being done to find out more details about this interesting topic.


When Aria Gmitter isn’t writing, she can be found traveling the country in search of a perfect cup of coffee. You can follow her on TwitterInstagram, and Facebook…and learn more about her work on LinkedIn.