Do women absorb the DNA of every man they have unprotected sex with?

Do women absorb the DNA of every man they have unprotected sex with?

I’ve been asked many times, mostly by worried pregnant mothers or potential baby fathers if a fetus’s DNA can be changed or effected by either another man’s semen while she is pregnant or from her sexual activities with previous partners.

The short answer is no.

There is a false belief that women absorb and retain the DNA of every man they have unprotected sex with. This belief has been spread through some articles, but stems from a 2012 research project that showed that the brains of some autopsied women had male DNA.  Some who heard this quickly jumped to the conclusion that they must have received this male DNA through sperm.

The truth is, this is called microchimerism and the explanation for the male Y chromosome being found in some female brains is not really that complex.

Pregnancy

When women become pregnant, they play host to another human with its own set of DNA. Some of this DNA gets absorbed through the placenta and remains with the woman for the rest of her life. If she has any male children then she will absorb some male DNA which explains why some of the women autopsied (aged 32 to 101) had male DNA in their brains even decades later.

The DNA a mother inherits from her child is often up to 10% of the free floating DNA in her blood stream. Often call foetal origin cells, they have also been found in the mothers skin and all major organ including the heart.

Blood Transfusions and Organ Transplants

When we receive blood transfusions or organ transplants, we are also receive some DNA from the donor. This is known as medical chimerism and is something the medical world has been aware of for a long time. If a woman receives a transfusion or transplant from a male, it is likely she will also absorb some male DNA.

Having an Older Male Sibling

If a woman has an older brother, the chances are her mother has absorbed some male DNA from him during her pregnancy and also passed it along to her daughter. This explains why some of the women autopsied who did not have any male children, blood transfusions or transplants, still had the presence male DNA.

Effects

Research suggests that having male DNA passed on to these women doesn’t affect them as far as femininity goes, but that it could have several beneficial effects:

  • Lower risk of some cancers
  • Longer life span
  • Better tolerance of successive pregnancies
  • Decrease risk of Alzheimer’s
  • Diminished symptoms of rheumatoid arthritis

So while many women have the presence of male DNA, it’s not because they were having unprotected sex. They do not carry the DNA of ex-lovers and thankfully are not bonded to them for life, however, they will be bonded even on a cellular level with their children til death.

Does the Baby’s DNA Change if the Mother Has Sex with Another Guy While Pregnant?

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I’m a strong proponent of the “there are no stupid questions” rule (in most cases), but can I propose that there are stupid statements?

The other day, an 18 year old client of mine, who is about two months pregnant with her ex-boyfriend’s baby, told me that she hasn’t told her new boyfriend that she is pregnant because she plans on changing the baby’s DNA from her ex-boyfriend’s to her new boyfriend’s by having repeated, unprotected sex with him. I nearly passed out from the shock of her ignorance!

I explained to her that it doesn’t work like that and tried to give her a crash course in human reproduction, but she quickly dismissed me, saying that she had a cousin who did it before (the cousin was probably never pregnant the first time to begin with, but that’s another story). I was so appalled that I could’t even debate with her because apparently she knew more than I did. It just made me more concerned about our youth and our future!

I took the liberty of researching her absurd question and was shocked to find that many people have asked the same question on forums such as yahoo answers! Not only that, but they asked such questions such as, “Does swallowing semen change the baby’s DNA?” ! What is wrong with these people? I know part of the problem is that we took sex education out of schools, so now we have a whole generation of children being raised not knowing the basics of human reproduction, human sexuality and anatomy and they will soon be raising and educating kids of their own! Scary! They’re not even concerned with real things that can “change” a baby’s DNA such as the mother’s diet and toxins such as smoking cigarette’s while pregnant. These things can alter DNA and make a child more prone to things like asthma, obesity, illnesses and allergies, but they nor can anything else turn “Mike’s baby” into “John’s baby” just because the mother and “Mike” no longer are together.

Few things scare me more than the state of our children and our future and the fact that they think they know everything when they at times don’t seem to understand the essentials of life.