Your immune system keeps you healthy and helps fight off infection. The classic perspective is that pregnancy suppresses your immune system. Advancements in our understanding of the immune system during pregnancy paint a more colorful picture. We now see the placenta as an immune regulatory organ. An intricate symphony is going on in your immune system to protect you and your baby during pregnancy. A more accurate way to describe it would be that pregnancy suppresses some aspects of your immune system and enhances others. Listen to this episode to learn how to support your immune system during pregnancy.

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How Your Immune System Works

Your immune system keeps you healthy and helps fight off infection. All immune cells originate in your bone marrow and live throughout your body. Immune cells are in your skin, blood, lymphatic system, mucosal tissue, and some organs.

Your immune system has two parts—your innate and adaptive immune systems. The innate immune system is the first to recognize danger from pathogens or viruses. Innate immunity cells respond quickly, create inflammation, and activate your adaptive immunity. Your adaptive immune system has your B and T-cell receptors, which can identify specific pathogens. B-cells make antibodies, and T-cells kill infected cells and activate or recruit other immune cells. Your adaptive immune system recognizes pathogens you have been exposed to in the past and gives you immunity moving forward.

How Pregnancy Changes Your Immune System

The classic perspective is that pregnancy suppresses your immune system. This suppression is designed to keep your body from rejecting your baby during pregnancy since your baby is foreign. This is a very simplified and basic explanation. Advancements in our understanding of the immune system during pregnancy paint a more colorful picture. In more recent understandings, we see the placenta as an immune regulatory organ. The placenta secretes antiviral molecules, transports antibodies from you to your baby, and can recognize pathogens and alert your immune system. For more in-depth information, see this article.

An intricate symphony is going on in your immune system to protect you and your baby during pregnancy. Perhaps a more accurate way to describe it would be that pregnancy suppresses some aspects of your immune system and enhances others. Scientists are working to understand better how your immune system changes during pregnancy. Some recent research shows a precise timing of immunological events occurring during term pregnancy. There is also research showing that hormones like estrogen, progesterone, and hCG help to regulate your immune system during pregnancy. More research shows that some changes in the immune system can help detect issues like preeclampsia.

Also, remember that your body is working incredibly hard right now. Pregnancy affects every system in your body. Your caloric intake and energy requirements are higher; you carry more weight, produce, and circulate more blood. Plus, making room for your baby puts extra pressure on other organs, impacting digestion and lung volume. You are building a human.

If you were training for a marathon, you would be taking additional steps for your health. Basic things like eating well, staying hydrated, taking a high-quality prenatal vitamin, exercising, and ensuring plenty of rest are crucial.

Taking Care of Your Immune System

I do not want to overcomplicate the basic building blocks of your immune system. If any of these pillars are out of wack, it will affect your health, and no amount of supplements or superfoods will make up for that. Before you reach for any immune-boosting supplement, get the basics in order. These are not difficult, but you have to prioritize these if you don’t already have good eating, sleep, hydration, and exercise habits.


Sleeping well is critical to support your immune system. You can do everything else right; if you lack sleep, your immune system will not function optimally. There is a past episode with tips for sleeping during pregnancy. This is especially crucial when you are likely experiencing fatigue in the first and third trimesters. When your body tells you you need extra sleep, please get more sleep. You need it, and your baby needs it.

Your sleep and immune function are closely linked. When your immune system is activated, it can alter your need for sleep, affecting both your innate and adaptive immune systems. Plus, there is a lot of research linking poor sleep to adverse pregnancy outcomes. During pregnancy, sleep deprivation has been associated with more prolonged labor, elevated perception of pain and discomfort during labor, higher cesarean rates, preterm labor, and higher levels of pro-inflammatory serum cytokines. If I had to pick one thing to focus on to support your immune system, it would be sleep.

It is not too late to start now if you do not already have healthy sleeping habits. Start with only going to bed earlier. Set a time to start winding down, put screens away, relax, and build a nighttime routine. You may have already thought about what you want your baby’s nighttime routine to be. You also need a nighttime routine. That can be turning your phone off, putting on pajamas, reading a book, going through a skincare routine, brushing and flossing your teeth, or listening to a podcast. If you have an iPhone, use the Sleep settings in the Health app for reminders on when to start winding down in the evening.

In the nine months you are pregnant, you will spend over 2,000 hours sleeping. That is a lot of time to be uncomfortable. Please make adjustments to your bed or your bedroom to be as comfortable as possible.

As your belly grows during pregnancy, you may change your preferences for sleeping positions. Use pillows to support your back, knees, or belly. You can get a pillow specifically designed for pregnancy. Investing in a pillow or some blackout curtains can make a big difference. In my first pregnancy, I put off buying a support pillow because I didn’t want to spend the money. The second time around, I did not make the same mistake. The more comfortable you are, the better you will sleep.

Blue light can negatively impact your hormones and sleep, and ideally, you should limit your exposure to blue light, including all electronic screens, for a few hours before bed. You can also use blue light blocking glasses to limit exposure after sunset. Stacking small habits can lead to significant improvement in your sleep hygiene. Start with one or two improvements and go from there. Check out this episode for more sleep tips.


All cells in your body require nutrients to function at optimal levels, including your immune cells. You want to eat healthy whole foods as much as possible. If finding fresh fruits and veggies is challenging, buying them frozen is a good option. Eating well is a matter of habit, and it can be a big chore if you don’t have the healthiest eating habits now. The key is to make it easy to eat healthily. Start by buying healthy foods and keeping your kitchen stocked so you are less likely to pick up unhealthy fast food or takeout. You can also meal prep and plan. It is a lot easier to eat a healthy meal when you plan for it. If you are making a salad for lunch, make two or three salads and store them in your fridge for the next few days. If you are making a healthy dinner, make extra to eat for lunch tomorrow. The less of a chore to eat healthier, the easier it will be. Remember, you should get most nutrients directly from your diet, not supplements.

Staying Hydrated

Every function in your body requires water. It helps regulate body temperature, acts as a solvent for vitamins and nutrients, helps with digestion, and eliminates waste. Your immune system also requires hydration to function correctly, and if you are dehydrated, it will impact your immune system.

You have increased requirements for how much fluids you should consume during pregnancy. The general recommendation is to drink ten 8-ounce cups (2.4 liters) of fluids daily. When you are breastfeeding, that increases to 13 8-ounce cups (3.1 liters) per day. If you are exercising or are in hot weather, you may need to increase your consumption of fluids to stay adequately hydrated.

The best beverage to drink will always be water. That is true, regardless of whether or not you are pregnant. In reality, we get fluids from more than just water. Your diet may provide up to 20%-30% of your daily fluid needs. This largely depends on what you are eating and will be higher in diets high in fruits and vegetables. Lettuce and cucumber are 96% water. Fluids in food can also come from sources like eggs, which are 75% water. Even a chocolate chip cookie is about 7% water. Learn more about staying hydrated here.


Exercise has endless benefits in every stage of your life, especially during pregnancy. Exercise also benefits your immune system in a few ways. One is that a temporary rise in your body temperature may help prevent bacteria growth. When you work out, antibodies and white blood cells are released more quickly. Lastly, exercise is a natural stress reliever. Stress can harm your immune function, especially if it is chronic stress. For an in-depth analysis of the history of research on exercise and immune function, see this article.

review on walking during pregnancy states that only 14-23% of pregnant mothers meet recommended levels of physical activity during their pregnancy. Physical activity tended to increase from the first through the second trimester and decrease in the third. This makes sense because you may be dealing with morning sickness and fatigue in the first trimester, making it extra challenging to lace up your shoes and go for a walk or a run. The second trimester is usually the one where you will feel the best. Fatigue tends to kick in again in the third trimester, and your growing belly makes exercising more challenging.

If you are not already working out regularly, it is not too late to start. You can get a workout in so many ways without joining a gym or buying a Peleton. A great place to start is to go for a walk. Get outside, get some vitamin D, breathe some fresh air, and get your body moving. If the weather is cold and you are stuck indoors, there are more free resources now than ever for in-home workouts, and many are geared toward pregnancy. Nearly any form of exercise can be modified to be safe during pregnancy.

Other Ways to Boost Your Immune System

We covered the four fundamental pillars of supporting your immune system: sleep, diet, hydration, and exercise. Please do not skip over these or ignore them. If any of these things are missing, it will impact your immune function. Once these four building blocks are in place, you can stack other habits or supplements to support your immune system.

Reducing Stress

Stress is a mechanism we developed for survival, and our bodies react to stress in our environment. Getting an injury that creates a stress response may increase your immune system to fight off an infection that could happen in that injury. Today, our environment has changed a lot. We are often subjected to stressors that alter our immune function when we do not need it. It turns out that stress from taking a test can dampen your immune response. Getting an alert on your phone doesn’t require a flight or fight response, but it still triggers that same mechanism. This is an example of our evolution not changing as quickly as our environment. Our immune system is closely linked to stress levels.

A meta-analysis of 293 studies examined different types of stress and how they impacted immune function. Any kind of stress changes how the immune system operates, and the most impactful was chronic stress, which negatively affected almost all functional measures of the immune system.

Being pregnant can be stressful. In the nine months you are pregnant, your body is going through more changes than it ever will in such a short time frame. Your hormones are fluctuating, which can make your moods and emotions all over the place. Your mental health is especially vulnerable during this time. You have a baby coming, and your life will change significantly. Which means there is a lot to learn and think about. Your brain is likely running in high gear. This is a time of significant transition in your life.

Self-care and reducing stress is more important now than it will ever be. You must take care of yourself because no one will do that for you. You may be fortunate to have people who do thoughtful things for you, but no one will prioritize your physical and emotional health like you can and should. Make it a habit to engage in activities that reduce your stress. By practicing these now, you will also have better tools to deal with stress as a parent. You know what works best for you to reduce stress. It could be walking, meditating, practicing mindfulness, listening to music, or doing yoga. Please make time for yourself to relax. You can learn more evidence-based techniques to reduce stress during pregnancy in this episode.


Research shows that probiotics can influence your immune function. Probiotic-rich foods include fermented foods like sauerkraut, kimchi, or kombucha. Yogurt and kefir are high in probiotics. In addition to having probiotic-rich foods in your diet, you can also take a probiotic supplement. There is even some evidence that taking a probiotic can reduce your chances of getting group B strep.

Your gut is also part of your neurological system, specifically your enteric nervous system. You may have heard about the gut being called the second brain. 90% of the fibers in your vagus nerve carry information from your gut to your brain. Your gut creates 90% of serotonin and 50% of your dopamine. Mood swings tend to be expected during pregnancy with all of the hormone changes you are going through, not to mention stress and anxiety. The better your body is at regulating your moods before your pregnancy hormones go crazy, the better. For more info on probiotics and pregnancy, see this article.

Immune Support Vitamins & Supplements

One way you can support your immune system is by taking a high-quality prenatal vitamin. A good prenatal vitamin will ensure that you meet the requirements for all the essential vitamins and nutrients you and your baby need during pregnancy. Plus, it will ensure you get all the nutrients your immune system requires to function optimally.

Evidence that nutrient deficiencies like zinc or omega-3s can negatively impact your immune system. If you are eating a healthy diet and taking a quality prenatal vitamin that includes omega-3s or a separate omega-3 supplement to ensure you are not deficient.

If you want to include an additional immune support supplement, there are a couple of things to remember. First, please run any supplements by your doctor or midwife, even if they are homeopathic, natural, or available over the counter. Many supplements include a warning to consult your health care practitioner if you are pregnant or nursing. This warning appears on the labels of products even if they are considered safe during pregnancy. Second, no immune support supplement will replace a poor diet, dehydration, or lack of sleep or exercise. Please prioritize those basics before considering adding additional supplements to your diet.

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