Memories from Pregnancy

“Mom Genes: Inside the New Science of Our Ancient Maternal Instinct”

There is a two-way cell movement between mother and baby via the placenta during pregnancy in placental mammals. The presence and persistence of fetal cells in maternal tissues are known as fetal microchimerism (FMc)

The scientific phenomenon of FMc has been the subject of study since the early 1900s when fetal cells were identified in the lungs of women with eclampsia. In the 1960’s studies pointed to fetal hematopoietic cells in healthy and sick women. In 1981, fetal cells were found in the maternal tissue of mice prompting research on FMc.

Most fetal cells gradually disappear from the blood circulation during the first weeks post-gestation). But a small proportion of fetal cells have been found integrated into maternal tissues up to three decades after delivery in humans). Fetal cells cross the placental barrier and enter the maternal circulation, where they can survive, migrate, and integrate into different maternal tissues- skin, liver, brain, heart, spinal cord, lung, lymph nodes.  Scientists studying fetal micro-chimerism have autopsied brain tissue of mothers and discovered evidence of Y chromosomes presumably belong to their sons.

Scientists are still trying to work out what these cells do for us or to us.  The fetal cells embedded in our hearts may help new mothers survive heart attacks. FMc may have a beneficial role in maternal health, participating in tissue repair and cell replacement. In contrast, FMc may have a detrimental role in maternal health, found in many post-pregnant women with autoimmune diseases rheumatoid arthritis. For more information click here.

The phenomenon of these cells has recently been written about by Dr Abigail Marie Tucker MD -an Obstetrics and Gynaecological specialist in Willoughby, Ohio.  In her new book “Mom Genes: Inside the New Science of Our Ancient Maternal Instinct”, Dr Tucker writes: Moms: You shaped your children, but the reverse is true, too - down to your very cells.  Read more.

Maternal-fetal cell transfer between mother and fetus in placental mammals Fetal cells (pink circles) traffic into and set up in the maternal organism (FMc). Maternal cells (purple circles) also traffic into and remain in the fetal body (MMc).