The Immune System and Pregnancy: A Step-by-Step Guide

You might not think that the immune system has much to do with pregnancy, but they're very much interconnected. Your immune system goes through some intense changes when you're pregnant. In fact, the immune system and pregnancy have an incredible symbiotic relationship that helps you get pregnant, stay pregnant and deliver your baby, while simultaneously leaving you more susceptible to illness. Here's what you need to know:

Pregnancy Alters the Immune System

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.

In order for an embryo to implant successfully, immune cells flood into the lining of the womb and cause inflammation. The heightened state of the immune system lasts for the first 12 weeks of pregnancy to allow for the fetus to get fully established.

Over the following 15 weeks, the mother's immune system is repressed to allow for the fetal cells to grow and develop. Some of these fetal cells have antigens from the father that would be at risk of attack if the immune system was running at full speed. An aggressive immune system returns near delivery, when inflammation helps with the labor response.

You're More Likely to Get Sick During Pregnancy

With your immune system in an altered state, you're more at risk for certain illnesses, such as colds, the flu, food poisoning and urinary infections. According to Dr. James Betoni, board-certified expert in high-risk maternal fetal medicine and OBGYN in Boise, ID, "The alterations in the immune system result in increased susceptibility to certain viral, bacterial and parasitic infections." Rest assured that most babies aren't harmed if their mother gets sick during pregnancy. But some infections can be transmitted to babies through the placenta or during birth, and when that happens, it may have serious consequences for the baby.

How to Avoid Getting Sick While Pregnant

You can't avoid all sources of illness while you're pregnant. But you can take certain steps to make it less likely that you'll get sick and to reduce the risk of serious problems for you or your baby:

• Stay up-to-date on vaccinations. Dr. Roshan stresses the importance of 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 and eat a balanced diet. According to Dr. Betoni, prevention is key. Vitamin C and Vitamin B6 can boost your immunity by increasing the body's natural production of interferon. Dr. Betoni recommends getting these vitamins from natural sources. For example, green vegetables and chick peas are high in B6.
• Take proper precautions. Basic precautions like washing your hands, not sharing glasses or utensils, and staying away from sick individuals will reduce your risk of coming down with an illness.
• See your doctor. If you do get sick during pregnancy, schedule an appointment with your doctor to ensure the health of you and your baby. Many over-the-counter remedies are relatively safe in pregnancy, but all medications should be cleared by your doctor.

The immune system and pregnancy have more to do with each other than you'd think. Check out some more tips on handling infections during pregnancy.