Researchers are forever discovering new ways that the human body interacts with pregnancy. It's a miraculous phenomenon that a woman's body can go through such complete and utter changes all the while growing and delivering a perfect human being.
The latest discovery has shed light on the function of the thymus and the role that it plays in a woman's body during pregnancy. The thymus is an organ of the immune system. It is within the thymus that T cells grow and mature. Those T cells are incredibly important when it comes to the human body being able to fight off invaders. Now science is shedding more light on how the thymus can protect a mother against infection all while tolerating the greatest of foreign invaders: a growing baby. It doesn't sound charming to refer to a fetus as an intruder, but regarding immunology, it is precisely that because half of the fetus's cells come from the father, not the mother.
Researchers have long looked at the role of the thymus in healthy pregnancies in mice. Because of what researchers observed there, it has been generally assumed that the thymus becomes smaller in a pregnant woman and produces fewer T cells. Scientists studied the output of different types of T cells in the blood of 56 pregnant and 30 non-pregnant women. They focused primarily on a specific type of T cell known as regulatory T cells. They discovered that contrary to previous beliefs, the thymus does NOT shrink in size when a woman becomes pregnant. Furthermore, the T cells in an expecting woman increase, not decrease. These results help the medical community better understand how a woman can carry a fetus within her body while still able to fight off infections.
The discovery goes past pregnancy, however. It gives scientists great hope that they can better understand certain debilitating, autoimmune diseases in the future. MS, for instance, impairs the thymus and allows for fewer T cells to be created. Pregnant women who have MS often notice that their symptoms lessen during pregnancy. This leads researchers to wonder exactly how the thymus functions during the before, during and after stages in a woman with MS.
A lot seems to be happening in the science community regarding their understanding of autoimmunity, and this discovery is only the tip of the iceberg. What lies ahead, researchers aren't exactly sure, but one thing is definite. The human body indeed is a wonder.