Forever connected: Mary, Jesus and the mystery of fetal microchimerism

Science and faith are often thought of as enemies. Nothing could be further from the truth.  Science and faith complement each other. Though given by grace, faith uses the experience, knowledge and material of human life to show us the wonders of God who loves us infinitely and whose ways and thoughts are inscrutable. As it says in today’s first reading from Isaiah (55:9):

For as the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts.

A fascinating insight has been offered by science into the mysteries of human reproduction.  The term fetal microchimerism refers to the persistence of a small number of fetal cells in a mother's body after pregnancy. Research has shown that these cells can remain in the mother's blood and tissues for decades after childbirth.

In mothers who have carried a male child, cells containing Y-chromosome DNA

have been detected in various maternal tissues, including the heart, liver, lungs, spleen, kidneys, thyroid, and skin.  Evidence suggests that fetal microchimerism can also occur following miscarriage or abortion. See, for example, a published article by Bianchi et al. (2021), ForeverConnected: The Lifelong Biological Consequences of Fetomaternal andMaternofetal Microchimerism as well as Peterson et al. (2012), Prospective assessmentof fetal–maternal cell transfer in miscarriage and pregnancy termination.

There is much that we do not know about human physiology. However, it is clear that there is material evidence of a remarkable biological connection between mothers and their children.

Pushing the theological envelope a little, it seems to me that the bond between Mary and her Son, Jesus, was both physical and spiritual. Modern research into fetal microchimerism suggests that cells from a child may remain in the mother's body for many years after pregnancy. While we cannot know scientifically whether this occurred in Mary's case, it is possible to speculate that the humanity of Jesus was united to hers in a uniquely intimate physiological way. Mary carried within her the incarnate Son of God, who is truly God and truly man. In this sense, she was the first person to bear within herself Jesus' body, blood, soul and divinity, long before Christ instituted the sacrament of the Eucharist. Though distinct from sacramental Holy Communion, Mary's union with Christ remains unique in the history of salvation and recent scientific research offers an intriguing biological analogy that resonates with this theological insight.