“I Was in My Mom”

Mystery of Motherhood Revealed by Science


Children sometimes joke, “I think my mom is a god. Even though I did it secretly, somehow she knows it was me.” “Not only she knows when I’m joyful and happy, but she also knows when I’m ill, lonely and sorrowful. It’s as if she knows me more than I know myself.” That is not all. She even defends her children despite the threat of death.

We do not need to mention the case of the 27-week-old premature infant that came back to life just by being held by his mother for two hours to display the miracle of mothers who have saved their children on the brink of death. Mothers fear nothing and can accomplish anything for their children. This is called Motherhood. The power of motherhood which bursts out from a delicate body! Where does this strength come from?

A Mother’s brain identifies her with her children

To answer the aforementioned question, an experiment was conducted for the first time regarding the love of a mother in May 2011, which was broadcast through an educational channel. The psychology department of Korea University led the experiment, using fMRI (Functional Magnetic Resonance Imaging) for brain scanning.

In total, 22 mothers who had children in middle school participated in this experiment; eleven were Koreans, and the other eleven were Americans. The duration of the experiment was ten minutes long, in which around 150 adjectives were given regarding personality and emotion. The mothers were to select the words that they thought described them. They were then told to select the words that they thought described their children, and lastly the words that described others.

This experiment reflected the difference in the mothers’ thoughts concerning themselves, their children, and others.

The human brain uses what is called the Medial Prefrontal Cortex when giving an opinion about oneself. This region of the brain, which deals with social information, is used when a person describes thoughts of themselves. On the other hand, the Dorsal Medial Prefrontal Cortex is used when a person gives an opinion about others.

During the experiment, the participating mothers’ brain activity was visible via brain scan. When the mothers were selecting the words that they thought described themselves, the medial prefrontal cortex—the region of the brain, which is associated with social information—was active. And as anticipated, when selecting the words that they thought described others, the dorsal medial prefrontal cortex was active.

Then, as what do the mother’s brains recognize their children who are not themselves or others? The result of the experiment was amazing. When the mothers judged information about their children, the medial prefrontal cortex—the region of the brain, which becomes active when they think about themselves—was active. Korean moms and American moms showed the same response.

Then what did this result tell about maternal instinct? It shows that mothers consider themselves and their children as equal beings. In other words, mothers’ brains recognize their children as another one of themselves, like a clone.

About this result, the experts in psychology stated, “The mother recognize her child as an equal to herself in her brain,” and they added, “Universally, mothers think of their children as themselves; therefore, maternal instinct does exist biologically.” The broadcast show concluded that since mothers regard their children as themselves, mothers can have infinite love toward their children—the love that even disregards death.

Then, why is it that the mothers’ brains recognize their children as their equals? Wouldn’t it be because there is a strong bond between mothers and their children since birth? When we examine the results that scientists have laid out, this must be the reason.

Picture 1. The activated brain region when a mother judges about herself (medial prefrontal cortex, colored in yellow). The activated brain region when a mother judges about others (dorsal medial prefrontal cortex, colored in blue).
Picture 2. The activated brain region when a mother judges about herself and her children (the same part)
✽ Images are from EBS TV Documentary “Mother Shock” Part 2: “There’s a Child in Mom’s Brain.”

Microchimerism, the bond between the mother and children

According to one scientific experiment, mothers and their children are intertwined by a mysterious mechanism called microchimerism.

Micro means small. Chimera 1 means synthesis of two or more elements having different origin. All mammals share their DNA and cells with their fetuses while they are pregnant. Microchimerism is the presence of a small number of cells that originate from another individual and are therefore genetically distinct from the cells of the host individual.

1. The term chimera originated from the creature with the head of a lion, the body of a goat, and the tail of a snake in Greek mythology. (Common Sense Dictionary Published by Parkmungak, 2013)

It is the same with humans. All people have the cells of their mothers within them which they got from the time they were in their moms’ wombs. About 60 years ago, scientists discovered maternal microchimerism which is the phenomenon of a mother’s cells laying roots inside her fetus.

A report at that time showed that the skin cancer cells of a mother were shared with the fetus. From then on, biology experts began to understand that there are ways for the maternal cells to be shared with the fetus as well. An immunologist, J. Lee Nelson along with some of his colleagues at the Fred Hudchinson Cancer Research Center in Seattle, U.S., did a blood test of 32 healthy females and discovered that 7 of them had the white blood cells of their mothers.

Then would it be possible for the fetus to share cells with the mother? Yes, it is. During pregnancy, the mother and the fetus exchange cells mutually.

Scientists discovered that mothers that have experienced pregnancy have their children’s cells in them. Receiving cells from the fetus, which is called fetal cell microchimerism, was discovered in 1893 by a German pathologist who found the fetal cells in the lungs of the mothers who had died of high blood pressure during pregnancy. Afterwards, Leonard A. Herzenberg and his colleagues at the medical department of Stanford University discovered the Y chromosome, which determines the fetus as male, in the blood cells of women who were pregnant with sons.

Women have two of X chromosomes. Therefore, it was sure that their Y chromosome originated from their fetuses during their pregnancy. Also, Diana W. Bianchi, a geneticist at Tufts Medical Center, found male DNA in the mothers that had experience in giving birth to boys.

Based on the research results, the microchimeric cells between the mother and the fetus were found in many different places such as the heart, liver, lung, kidney, marrow, skin, blood, thyroid, and so on. Scientists explain that the Y chromosome, which is found in the mother’s blood, is from the male fetus during their pregnancy. The DNA of the fetus can be found in the blood of 80 to 90% of pregnant women. This is because the fetal cells enter the mother’s body by passing through the placenta when it is in the womb.

However, the fact that the Y chromosome is found in the female’s body does not mean that the mother exchanges cells only with her son. The reason it is difficult to find the female fetal cells in the mother is that both hold the X chromosome. Scientists explain that female fetuses too leave trace in many regions of their mothers’ bodies just as male fetuses do.

Microchimeric cells between the mother and the fetus are found in many parts of their bodies. (The part where the microchimeric cells settle between the mother and the fetus)
J. Lee Nelson, Your Cells Are My Cells, Scientific American, Feb. 2008

The cells of children living in their mothers

What role do the cells of child, which have planted themselves in the mother’s body through the microchimerism, play? Generally, the cells that are transferred into others through marrow transplants or transfusion cause bad side effects because of immune rejection, or disappear within some time, being attacked by the defense mechanism of the immune system.

However, the fetal cells that migrated to the mother through microchimerism continue to increase in number and grow for years. The microchimeric cells are found in the mother’s blood even 25 years after her childbirth, and in the hepatic tissue cells after 20 years.

The microchimeric cells, which pertain in the blood of the mother even after her child delivery, get involved in the immune system. In this case, there are some negative effects such as causing illness, but it is known that most of the time, the fetal cells in the mother’s body would go into the mother’s injuries and regenerate tissues.

They say that the fetal cells act as a precursor cell (a stem cell that has developed to the stage where it is committed to forming a particular kind of new blood cell) in the process of regenerating tissues and help the mother’s body. In actuality, the fetal cells are proved to take on a great role in ameliorating or alleviating the mother’s breast cancer or rheumarthritis. Some scientists even say that the reason females live longer than males is because of the fresh cells that they got from the fetus.

The fetal cells, which flowed into mother’s body, also help the mother recover her heart problems. A team of doctors including Hina Chaudhry at Mount Sinai Medical Center in New York held an experiment to examine why women who have experienced pregnancy recover faster than others from cardiomyopathy or heart attack and to see if the fetal cells provide assistance to this.

As a result, in November 2011, an academic journal of the American Heart Association wrote the discovery that the cells of baby mouse which entered the heart of the mother mouse during pregnancy became the new type of myocardial cells and provided assistance of recovery in its heart. Doctor Chaudhry stated, “The fetal cells that enter the mother’s brain will also become the new nerve cells,” and she continued, “There’s no doubt that the fetal cells provide assistance in protection of the mother’s brain from illness.”

A mother lives all her life with her children in her brain

Until recent days, scientists insisted that the fetal microchimeric cells which were laid out in the mother’s body were found in all parts of the body except the brain in case of humans; they thought that it was impossible for microchimerism to occur in a human brain between the mother and the fetus because of the blood-brain barrier.

All humans have the blood-brain barrier in the brain. Just as the name explains, this is a barrier between the blood and the liquid which wraps the brain in order to protect it from any outside objects that attempt to enter the brain. Therefore, it blocks off any type of medicinal chemicals, pathogen, and harmful substances that go toward the central nervous system through the blood. The scientists thought that there was no room for the inflow of the fetal cells into the mother’s brain because this blood-brain barrier prohibits the exchange of cells between the mother and the fetus.

However, scientists discovered the Y chromosome in the brain of a female mouse. There was no doubt that the female mouse had received this chromosome from its male fetus during pregnancy. From this, the Fred Hudchinson Cancer Research Center started an experiment, questioning the possibility of the fetal cells migrating to the mother’s brain and if so, how it got past the blood-brain barrier. On September 26, 2012, they presented their results through the international scientific journal PLOS ONE. The conclusion was that the Y chromosomes were found in many regions of the brains of woman that had experienced pregnancy. This was the first discovery of male DNA in women’s brains.

The team of Dr. William F. N. Chan at the Fred Hudchinson Cancer Research Center gathered brain tissues of 59 women who passed away in the age range of 31 to 101 to see if there were Y chromosomes present. As a result, the research team found out that about 63% of the women had Y chromosomes in their brains. They stated that the Y chromosomes were transferred from the fetus during pregnancy. Dr. Chan shared in the media, “When a woman is in her pregnancy, there is a change in the blood-brain barrier, and the tissues of the male fetus can easily enter her brain. Through this experiment, we have discovered that such microchimerism is possible.”

The research team added that just as the fetal cells provide assistance in the recovery of the mother’s illness, the fetal cells in the mother’s brain provide a good amount of assistance in recovery from Alzheimer’s disease or dementia. The women who have dementia are found to have less fetal cells in their brains than the women who do not have dementia. This is because Y chromosomes provided help in protecting the mother’s brain.

They also discovered that the fetal cells which passed through the blood-brain barrier remained in the mother’s brain for long periods of time. In this experiment, the oldest woman who was found to have the Y chromosome was 94 years old. This proves that fetal cells pertain in the mother’s brain even for several decades after her pregnancy. This means that the mother lives her entire life with her son in her brain.

Mother, programmed to live for the life of children

Many scientists have come to the same conclusion that when a woman becomes a mother, she becomes a completely different being. When a woman becomes pregnant, she comes to have a warrior cast of mind as if she is a guardian angel existing for her child. Experts state that the fetal cells play an important role in changing the mother into a warrior like Wonder Woman when it lays its roots in mother’s body. Psychologists also explain, “The fetal cells enter the veins of the mother and flow into a special part of the brain which brings about the desire to protect the child.”

Motherhood brings forth a maternal instinct.

From the time when a mother has a child, she lives as if her purpose is only her child, making much effort for the sake of the life of her child. She completely disregards all the pain and injuries that she receives in the process. She is willing to go through any kind of pain and sacrifice when it comes to her children, even to lay down her life. Such love and sacrifice is only possible because she is a mother.

God has designed that a child should stay in his mother’s body for nine months, and that during the period of time, he leaves his cells in many different parts of his mother’s body including her brain. Therefore, a mother has been programmed to live her life with the cells from her child in her body, only for the sake of her children, even forsaking her own life.

In this manner, a mother has been created as the one who meets her end only after taking care of her children and protecting their lives with great care, love, and sacrifice.

“I will make your pains in childbearing very severe; with painful labor you will give birth to children.” Ge 3:16

“Eve . . . She would become mother of all the living.” Ge 3:20

A mother is a being chosen to carry her child for a long period of nine months, to bear him with severe pain, and to live only to protect her child’s life. After unveiling the mystery of motherhood and maternal love which allows a woman even to willingly forsake even her own life for the well-being of her child, we have discovered that our mothers have us in every part of their bodies. They have us in their brains all their lives.

1) EBS TV Documentary, Mother Shock Part 2: There’s a Child in Mom’s Brain, May 31, 2011
2) J. Lee Nelson, Your Cells Are My Cells, Scientific American Feb. 2008, pp. 72–79
3) News Release of Fred Hutchinson Cancer Research Center, Men on the Mind: Study Finds Male DNA in Women’s Brains, Sept. 26, 2012
4) William F. N. Chan, Male Microchimerism in the Human Female Brain, PLOS ONE, Sept. 26, 2012
5) Medical News Today, Female Brain Contains Male DNA, Sept. 27, 2012
6) Lee Yeong-wan, In Mother’s Brain, There Live Her Sons and Daughters, Chosun Ilbo, Oct. 10, 2012