There’s nothing like a bond between a mother and her son, but now the connection goes further than scientists originally thought. According to a new study from the Fred Hutchinson Cancer Research Center, having a baby boy may lead to male DNA lingering in the mother’s brain.

The study, published in the journal PLoS ONE, showed that when a woman is pregnant with a baby boy, some of his DNA can be transmitted through the mother’s body and up to her brain. This condition is known as 'microchimerism' and the cells can hang around a woman's body for decades: male DNA was reportedly discovered in the brain of a 93-year-old woman after she died!

This is the first to find male DNA in women’s brains, although previous studies have found male cells in women’s blood, bone marrow, hearts, and lungs, among other organs.  While it could lead to higher odds of bowel and skin cancer, male DNA may help women fight breast cancer by boosting her immune response to help fight off infections. So far, they haven't been able to test to see if little girls also pass on their DNA in the same way.

via Livescience