By Brian W. Donnelly, M.D. — Pediatric Alliance —              OLYMPUS DIGITAL CAMERA

North Hills Division


This is such a great study!  Mothers give so much to their children.  Now we see evidence that the baby can actually give something useful back:

In this study, we provide the first description of male Mc [microchimeric cells] in female human brain and specific brain regions. Collectively with data showing the presence of male DNA in the cerebrospinal fluid our results indicate that fetal DNA and likely cells can cross the human blood-brain barrier (BBB) and reside in the brain.


It is thought that these cells are transported during pregnancy — from fetus to mother — through the placenta.  It’s also thought that cells can be transferred from mother to child in breast milk!

“I’m in you

You’re in me”

I can hear Peter Frampton sing it.  I can also hear my teenagers’ eyeballs rolling in their heads.

“Seriously?  Not another cheesy 70’s song!”

But it is sooo apropos…

In animal studies, the fetal cells acted similar to stem cells.  The cells settling in the brain differentiated into nerve cells, the ones in the heart forming heart cells.  There is also evidence that these microchimeric cells might influence the maternal immune system in positive ways (cancer) and negative ways (multiple sclerosis).

As John Donne put it :

“No man is an island

Entire of itself.

Each is a piece of the continent,

A part of the main.“


Thanks, babies, for your lovely little piece of the cellular continent!


Read an excellent review of this study in Scientific American here.

(Editor:  Read more from Dr. Donnelly here and here.)