“Key to a healthy pregnancy lies in the delicate interaction between the immune system of the mother and the developing baby” Read to know more…
About 80% of unexplained recurrent spontaneous abortions have an immunologic mechanism!
Immuno-tolerance and energy or absence of normal immune response is two important immunomodulation for the maintenance of pregnancy. Pregnancy confers a unique immunological state to the pregnant lady to prevent rejection of the fetus. Immune modulation during pregnancy is a complex process.
How does the placenta allow females to maintain the developing fetus in the reproductive tract for prolonged periods?
Successful pregnancy relies on the ability of the maternal immune system to change and adapt to every stage of pregnancy spread across all the three trimesters. It should be acknowledged that the immune modification occurs in all three trimesters of pregnancy and begins with implantation and formation of the placenta, followed during fetal growth, and lastly with parturition or the act of giving birth. Each trimester stage requires a unique immune response modulation.
Immunity in Pregnancy: The Untold Secret
What is the different immunological response in the three trimesters of pregnancy?
A successful pregnancy requires both an inflammatory and an anti-inflammatory immune response.
Pro-inflammatory stage of implantation and placenta formation
The first trimester of pregnancy involves the pro-inflammatory immune response. The process of implantation and placentation resembles the process of tissue injury and subsequent repair.
Anti-inflammatory stage of fetal growth
The second trimester of pregnancy, from weeks 13 to 27 involves rapid fetal growth and development. This anti-inflammatory stage includes maternal tolerance of the fetal allograft.
During pregnancy, the regulatory T cells (Treg) play a key role in maintaining an anti-inflammatory and anti-apoptotic environment to prevent cytotoxic immune response against placental antigens. Certain critical cytokines also control the production of the uterine derived Natural Killer cells during the early stage of pregnancy. The maternal macrophages aid in tissue regeneration during the development of placenta by actively secreting anti-inflammatory cytokines.
The post-pro-inflammatory stage for delivery of the baby
The nuclear factor κB (NF-κB) signalling pathway and the influx of immune cells initiate contraction of the uterus, separation of placenta and delivery of the baby.
Immune disorders in pregnancy loss
- Antiphospholipid Syndrome (APS) associated with repeated miscarriages and fetal death
- Conditions like diabetes mellitus and polycystic ovary syndrome
- Uterine anatomic abnormalities
- Genetic factors involving chromosomal translocations
- Blood coagulation
- Progesterone supplementation
- Leukocyte immunization therapy
Use of preconception aspirin and post-conception heparin to prevent blood coagulation.
Impaired cell-mediated immunity specifically in the second and third trimester of pregnancy protects fetal allograft and reduces the risk of pregnancy loss by the immune response.
Being affected by any kind of immune disorder does not necessarily indicate a crisis situation but with appropriate counselling and management, every lady can walk the beautiful journey of pregnancy.