Top Foods to Avoid During Pregnancy

If you are reading this blog post, congratulations! 

Although pregnancy brings so much anticipation and excitement, I know first hand that it also comes with a lot of anxiety and fear. There’s so much information out there and it can be extremely overwhelming.

I hope that this week’s blog post provides some clarity about how our body changes during pregnancy, and what swaps you may need to make to your diet to keep both you and baby healthy.

Please note that this is by no means a comprehensive list.  If you have questions about specific foods, beverages, or supplements, I recommend reaching out to your care provider or a registered dietitian for tailored guidance.

Immune System & Pregnancy

Before diving into the list of foods that are best avoided during pregnancy, let’s talk about why.

When you become pregnant, your body undergoes major changes to its immune system. So much so, that pregnant folks are technically a part of the “immunocompromised” population. Though this might sound scary, it’s actually a good thing!

Being immunocompromised essentially means that your immune system is weakened.  Having a weak immune system affects our ability to fight off illnesses. Your body undergoes these changes to protect your baby. If our immune systems didn’t adjust during pregnancy, our bodies might actually flag the baby as a threat (something we definitely don’t want).

Because of these changes, our risk of getting sick from certain foods and beverages increases during pregnancy.

Let’s dive into some of the biggest risks when it comes to food.

Foods to Avoid

1. Raw and Undercooked Meats and Seafood

You may already know that even for non-pregnant individuals, consuming raw meat and seafood products can be risky. Not surprising, this risk is even higher for pregnant folks. Raw meats and seafoods carry bacteria such as salmonella and listeria. 

If ingested, these bacteria can cause serious harm to pregnant individuals such as severe illness and increased risk for pregnancy loss.  You may be as surprised as I was to hear that during pregnancy, you are 10 times more likely to get listeriosis (an illness caused by listeria), than the non-pregnant population. 

The best way to keep yourself and your baby healthy is to use safe food handling techniques, and to cook your meats and seafood to safe internal temperatures. 

2. Unpasteurized products 

If you live in Canada, you’ll be glad to hear that most of our foods are pasteurized. Pasteurized foods are heated to specific temperatures for a set amount of time in order to kill harmful bacteria. This helps prevent illness and keeps our food from spoiling too quickly. 

Products like milk, cheese, yogurt, honey, and juice can contain harmful bacteria if not pasteurized. These are the same bacteria that can contribute to severe illness, miscarriage, premature births, and in some cases, stillbirths. It’s good practice to double check the food labels on these products to ensure they are pasteurized.

If you are traveling to other countries, or buying special types of cheese from a local cheese shop, there is a higher chance that these products may not be pasteurized. 

Some exceptions are semi-soft cheeses, blue cheese, and molded-rind cheese. It is best to avoid these even when pasteurized. They have a higher moisture content and lower acidity which creates a loveable growing environment for listeria. The best way to consume these cheeses is by heating them to 74 degrees celsius or higher right before consuming. 

3. Raw eggs

Who else is a cookie dough/batter sampler? (No shame here, I am certainly guilty of this). Although we may have survived most of our lives without getting sick from our sampling, pregnancy may be a good time to take a break. 

Raw eggs put pregnant individuals at risk for salmonella. Since the risk of contracting illnesses from food is higher during pregnancy it’s best to cook eggs thoroughly. 

Eggs should also be pasteurized. If you purchase eggs at the grocery store in Canada, this is likely not an issue. However, if you have some wonderful family friends with backyard chickens, or a farm stand down the road I would use caution. 

4. Raw Sprouts 

Many of us have heard about a food recall for sprouts. Although they are delicious (and nutritious), sprouts are frequently found guilty of being contaminated with bacteria and parasites. 

Sprouts (such as alfalfa, mung bean, clover and radish) are frequent culprits of food illness outbreaks because of the way that they are grown. Their growing conditions make it difficult to eliminate harmful bacteria such as listeria.

It is best to avoid sprouts during pregnancy, unless they are heated to 74 degrees celsius. Unfortunately, light cooking isn’t enough to kill the pesky bacteria. 

5. High Mercury Foods

Mercury is a metal that can be found in higher amounts in certain foods. All humans should be cautious of mercury consumption, but it can have an especially dangerous impact on your baby. Research shows that mercury can impact your babies lungs, kidneys, and nervous system (including their brain, spinal cord and nerves).

Mercury tends to be highest in certain fish such as tuna, shark, marlin, escolar, orange roughy, and swordfish. Consumption of these fish should be limited to no more than 5oz two times per month. 

6. Certain Sweeteners 

Are you familiar with saccharin (also known as Sweet’N Low)? Research has shown that Sweet’N Low is a mild carcinogen that is actually able to cross the placenta. Unfortunately, it is best to avoid this sweetener during pregnancy. 

Although there is no need to eliminate it completely, it is recommended that aspartame (Equal, NutraSweet, Nutra-Taste) be limited during pregnancy to no more than 1-2 servings per day. If you are consuming less than this amount then there is no need to worry, you and baby are perfectly safe!

7. Alcohol

I know it’s not technically a “food”, but I felt it was a good idea to include in the list. Alcohol is a known carcinogen. During pregnancy it is especially important to avoid consuming alcohol as it can cross the placenta and impact the growth and development of the baby. Sadly, there is no safe amount of alcohol to consume during pregnancy.

You’ll appreciate that glass of vino so much more after baby arrives!

Foods to Limit

1. Caffeine

As a dietitian, I’ve heard so many different takes on this topic during pregnancy. Many hear that caffeine is bad and think they need to eliminate it completely.

While it’s true that caffeine does cross the placenta, and that the baby cannot break it down the same way we can, research shows that 200mg or less is completely safe. You might be thinking ok great, but what the heck does that mean to me?! 

Let’s break down caffeine content in popular beverages:

• Espresso (1 shot, 1 ounce) ~63mg

• Cold brew (16oz) ~200mg

• Brewed coffee (8oz) ~80-10mg

• Black tea (8oz) ~50mg

• Green Tea (8oz) ~30-50mg

• Matcha (½ - 1tsp) ~ 38-176mg

• Pop (1 can, 12oz) ~30mg

If you frequent a particular coffee shop (e.g. Starbucks, Tim Hortons) it might be a good idea to check online for their nutrition information. 

2. Certain Teas

Before jumping into which teas are safe vs. those we should maybe consume with caution, I think it may be helpful to talk about why all tea is not created equal during pregnancy.

Non-herbal teas like black tea, green tea, and oolong are made directly from the leaves of tea plants. Herbal teas on the other hand can be made from the roots, seeds, berries, flowers, and leaves of a variety of plants, not specifically tea plants. 

Non-herbal teas are safe in small amounts during pregnancy, mainly due to their caffeine content. As long as you are keeping an eye on your caffeine consumption you can happily consume non-herbal teas.

Herbal teas are in a bit of a grey area. Though they are typically caffeine free and often linked with many different health benefits, the lack of research on certain herbs during pregnancy places them in the grey zone. 

It is ok to consume most commercially made herbal teas in “reasonable amounts”, though it is not very clear what this means. It is best to avoid any herbal teas that are not made commercially. When in doubt check with your care provider. 

The Natural Medicines Database is a great resource to check out as well https://naturalmedicines.therapeuticresearch.com/ 

3. Liver

This one is for all of my liver lovers out there.. I know there aren’t many of you, but this one is important! Although liver is a typically known as a healthy food, during pregnancy we need to be cautious of the high amounts of vitamin A it provides.

High amounts of vitamin A during pregnancy has been linked with birth defects. If you are a liver lover, it is a good idea to limit consumption to no more than 75 grams (2.5oz) per week. 

You’ve reached the end!

I know this week's blog post was a longer one, but I hope that you found it helpful. Don’t forget to remind yourself how great of a job you are doing. Pregnancy is no walk in the park! Congratulations again, your world is about to change for the better.

Which things were (or would be) the easiest and hardest for you to eliminate/limit during pregnancy? Let me know in the comments.