The Immune System: a Friend or an Enemy for Reproduction?
The immune system is multi-functional. It is important in fighting infections as well as healing wounds, repairing tissue and beginning the process of pregnancy (implantation). There is evidence that the immune system is crucial for pregnancy implantation and the formation of the placenta. Without immune cells, pregnancy could have a poor outcome including pregnancy loss (miscarriage).
The activity of the immune system varies from one person to another. A balanced immune system is important for a healthy human body. An unbalanced immune system can range from underactivity (deficient) to overactivity. The underactive or deficient immune system can lead to increased susceptibility to infection. However, an overactive immune system can be associated with autoimmune disease. This is when the immune system attacks its own body. Pregnancy and reproduction in general can be affected by the unbalanced immune system, either under- or overactivity.
How the immune system is important in pregnancy implantation?
The placenta is an organ that starts forming within the uterus and grows with the pregnancy. The placenta provides adequate blood supply to the fetus (baby). Once the pregnancy starts implanting inside the uterus, the immune cells will play an important role in formation of the blood vessels feeding the fetus. A few of these immune cells include:
- Natural killer cells
- Dendritic cells
- Macrophages
- Mast cells
Unhealthy or lacking immune cells can negatively impact the growth of the fetus during pregnancy.
The fetus is considered half foreign for a women’s body. While it has 50% of its genetics from the mother, the other half is from the father. It’s very important for the pregnant woman’s immune system to maintaining tolerance to the fetus rather than rejecting the fetus. Other immune cells such as T-cells will play an important role in immune tolerance.
How can the immune system become an enemy?
Research showed that increased activity of those immune cells or absence of immune tolerance may lead to abnormal immune response. This can impact the implantation and pregnancy overall. Those women can have immune system abnormalities such as:
- Overactive natural killer cells
- Elevated T-helper 1 / T-helper 2 cytokines ratio
- Autoimmune antibodies
A thorough medical investigation is important to identify the underlying problem(s).
How to treat this problem if immune abnormalities found?
Immune medications can be used to fine-tune the immune system. Some of these medications may include:
- Prednisone
- Plaquenil
- Tacrolimus
- IVIG
These medications can help make sure appropriate implantation occurs without any negative impact on the blood flow to the fetus.