Your body's immune system is on high alert during pregnancy - it has the vital job of protecting you and baby against disease.
Pregnancy is an invasive process that your immune system can see as a threat. How does your sophisticated immune system deal with the complexity of pregnancy.
'Pregnancy suppresses the body's immunity to safeguard the fetus and not reject it as a foreign body of pathogen. This works by lowering your immune response and means your body is less able to fight off infection and disease, making it vulnerable to colds and flu. In fact, the pregnant immune system has a finely-tuned symbiotic relationship that enables you to actually get pregnant, stay pregnant and have your baby, at the same time leaving you more susceptible to invading viruses.
Pregnancy alters your Immune System response
Although it was originally believed that the immune system weakens during pregnancy to avoid attacking the fetus, recent research conducted by Dr. Brice Gaudilliere in Science Immunology found that an aggressive immune system response is essential for implantation. His research has found that the strength or weakness of the immune system is precisely timed to achieve the best outcomes for both the mother and the child.
For an embryo to implant in the uterus successfully, immune cells must flood the lining of the womb and cause mild inflammation. This high alert of the immune system lasts for the first trimester of pregnancy to enable the fetus to make its 'home'.
Over the next trimester, the repressed immune system allows the fetal cells to grow and develop. Some of the fetus' cells will have antigens from the father, which would trigger an immune response if the immune system was in its normal state. The aggressive immune system returns closer to delivery, when inflammation helps with the labor response.
'Pregnancy suppresses the body’s immune system (to ensure the fetus isn’t rejected as something foreign) which means your body is less able to fight off infection and illnesses, making it more susceptible to colds and flu,' says leading UK nutritionist Dr Marilyn Glenville, author of Getting Pregnant Faster.
The placenta, an immunological barrier between mom and baby
The placenta allows nutrients and blood from the mother to reach her fetus and it also disposes of the baby’s waste through the mother. It also produces hormones and shields the baby against bacteria but not viruses.
Once the baby is born, neither the mother nor the child will need the placenta any more. It is delivered by the mother after the baby is born in what’s called the third stage of labour.
A gestating woman's body should reject a fetus, but it doesn’t
The immune system's only job is to detect foreign pathogens and foreign bodies, and attack them, whether they are germs, foreign substances or transplanted organs. So why doesn't it do its job and reject the unborn 'foreign body'.
Pregnancy hormones can temporarily reverse chronic conditions
Some autoimmune conditions benefit from the onslaught of hormones produced in a pregnant body. Multiple Sclerosis, a progressive demyelinating condition, where the nerve fiber coating is damaged and stripped from the nerves. Eight out of ten people affected by MS are women, so women's hormones were once suspected to be a causal factor in the onset of the disease. However, that is still inconclusive, but what we do know is that MS generally goes into relapse and many daily and regular symptoms experienced by women with MS 'disappear'. This reprieve is often short lived as there is an increased chance of another episode within 2-3 months after giving birth.
Psoriasis, is another condition that remits during pregnancy. It is a skin condition that produces red, scaly patches on the surface of the skin, caused by an overproduction of skin cells. There is no cure for psoriasis, but some women report a remission of their symptoms when they become pregnant. Some scientists attribute is to the unique ‘steroid-like' nature of some pregnancy hormones.
If a mother’s and baby’s blood types are different, it can cause problems
Do you know your blood type? In some states it is still a legal requirement for prospective heterosexual spouses to have blood tests. Premarital blood tests check for rubella (German measles) and venereal diseases. The tests can also reveal the presence of genetic disorders such as Tay-Sachs disease and sickle-cell anaemia.
The main purpose of the tests though is to check for blood-type compatibility between prospective biological parents. When a mother with Rh-negative blood carries a baby with Rh-positive blood, which can be inherited from the father, her antibodies can attack her fetus. This happens if the mother has been exposed to Rh-positive blood by carrying a Rh-positive baby before, her body will produce antibodies to the foreign blood and will begin destroying her baby’s blood cells during the pregnancy and even in the few weeks after she has given birth.
What can you do to help your immune system
- Get vaccinated against 'flu and rubella
Making sure you're up-to-date will all the vaccines before you get pregnant. While you're pregnant, be sure to get the flu vaccine during flu season and Tdap (Tetanus, Diptheria, Pertussis) vaccine in the third trimester to pass the immunity to the baby.
- Take prenatal vitamins. This will ensure you immune system has all the essential nutrients and minerals it needs.
- Eat a balanced diet. Prevention is key to good health. Vitamin C and Vitamin B6 can boost your immunity by increasing the body's natural production of interferon.
- Get plenty of Vitamin D. Pregnant women are advised to start taking vitamin D supplements as soon as they know they are expecting. This is essentially the Immune system's main vitamin for its health and proper functioning (vitamin D is actually a hormone, strictly speaking). Researchers in Denmark found that vitamin D plays a key role in the complex process where T-cells become 'primed' and ready to attack invaders and fight infection.
- Take proper health and hygiene precautions. Washing your hands, not sharing glasses or utensils, and staying away from sick individuals will reduce your risk of coming down with a transmittable disease.
- Don’t forget your zinc. Zinc is essential for sperm production and it plays an important role in helping to support your immune system too. Zinc supplements can help recover from colds and 'flu. The body needs zinc for the production, repair, and functioning of DNA,' adds Dr Glenville. Zinc is found naturally in many foods, including dairy products, some shellfish, beans, nuts and bread and cereal products, such as wheat germ.
We may not fully understand how the immune system can attack and protect at the same time, but a healthy immune response is one that will protect you and baby, and moderate its response to keep you both alive.