It’s no secret that every pregnancy a woman experiences leaves its impact on her forever. Experiencing a life growing inside of you and becoming a mother can change you forever. But did you know that fetal cells from every pregnancy remain in the mother, sometimes even 50 years later?
During pregnancy, fetal cells cross the placental wall and make themselves at home in the mother’s body. Sometimes some of the cells die off, while others stick around for decades. Dr. Kirby Johnson of Tufts University has been studying these fetal cells for years, wondering what their purpose was in the mother’s body.
It appears some of the fetal cells can often help in healing, especially in livers, and fight to keep the mother healthy. Conversely, other fetal cells can attack the mother, making ailments such as arthritis worse. There are many determining factors into why the cells behave as they do.
What produces these behaviors? Dr. Johnson sighed and said the list of explanations keeps getting longer. It could depend on the disease. It could depend on the type of fetal cell (they can be different). It may depend on the mother’s age, how many conceptions she’s had, or who the father was. (Fathers can be genetically similar to the mother or genetically very different, and that variance seems to matter.) (Source)
This is not where fetal cell swapping ends, either. The cells from siblings, mothers, and fathers can all be transferred from one individual to another. An older sibling’s cells can cross through the placenta and into the subsequent fetus. Similarly, the father’s cells, which make up half the fetus’ DNA, can enter into the mother as well.
The fetal cells from each pregnancy, flowing in a mother’s bloodstream, can be passed on to her successive kids. If we have an older sibling, that older sibling’s cells may be in us. The baby in a large family may harbor the genes of many brothers and sisters. My mother’s cells are in my body, and so are my daughter’s cells, and half my daughter’s DNA comes from her dad. Some of those cells may be in my brain. (http://jenapincott.com/)