Every new mom hears about foods to avoid in pregnancy. They’re told no lunch meat, no fish, no soft cheese!!
Is this all true? What is the reason for these recommendations? I’m here to break it all down for you.
The concern is food borne illness – according to the FDA a food borne illness is an illness that results from eating food contaminated with bacteria, viruses or parasites. Food borne illness is not fun when you aren’t pregnant, but it can be very dangerous when you are pregnant. Lets look at some specific food borne pathogens, why they are dangerous, where they come from and how to avoid getting sick.
First, let’s take a look at Listeria. Listeria is a sneaky bacteria that can grow at low temperatures, so simply refrigerating foods does not prevent its growth. Foods that have been known to be contaminated with listeria are ready to eat foods such as lunch meats, deli food, shrimp cocktails and other ready to eat sea foods. Additionally, listeria can grow in milk and this is why pregnant women are often told to avoid unpasteurized milk products -raw milks and cheeses can be dangerous. Listeria can also be in the soil and the manure of animals infected with listeria, so unwashed fruits and vegetables can carry listeria.
Listeria can cause an illness called listeriosis. Symptoms include fevers, headaches, nausea, vomiting, sore neck, confusion and loss of balance. Pregnant women are about 10 times more likely to get listeriosis than nonpregnant adults. Most pregnant women who contract listeriosis will have no symptoms, but can pass the bacteria to their unborn baby. The effects of listeriosis on a fetus in first trimester can cause miscarriage. In later pregnancy listeriosis can lead to preterm delivery, low birth weight infants or children with significant health problems such as learning delays, paralysis, seizures, blindness, and defects to the brain, heart or kidneys.
Because the majority of women who contract listeriosis have no or only very mild symptoms, prevention is vital. Food safety is very important. Be sure your refrigerator is set at 40 degrees or colder. Put all left overs in to the refrigerator immediately. Discard any food that has been left out for 2 hours or more. Discard all foods that have passed their “best by” or “expiration” date. Wash all fruits and veggies. Be vigilant in preventing cross contamination in the kitchen during food prep; use separate cutting boards and knives for meat vs fruits and vegetables.
There are some foods that pregnant women should completely avoid to prevent listeriosis;
- Hot dogs
- Deli meats
- Refrigerated smoked sea foods: smoked salmon that has to be kept in the fridge
- All unpasteurized milk products – double check any soft cheese to be sure it says it has been pasteurized.
- Refrigerated pâtés or meat spreads.
It is safe to eat:
- Canned or shelf-stable (able to be stored unrefrigerated on the shelf) pâtés and meat spreads.
- Canned or shelf-stable smoked seafood.
- Pasteurized milk or foods that contain pasteurized milk.
The next pathogen that can be found in food is Toxoplasma. Toxoplasma is a parasite that is found in under cooked meats such as pork, lamb, venison and moose meat. It has also been found in contaminated water. Cat feces can contain toxoplasma as can soil. Toxoplasma can get into the body if these are touched and hands are not washed before eating or touching ones face. About 50% of toxoplasma infections come from food and the other half from contaminated hands/water.
Many people are immune to toxoplasma before pregnancy. Women who have spent much of their lives around cats have a fairly good chance of being immune. If you have cats it is very reasonable to ask your midwife or care provider to test your toxoplasma immunity.
If you are not immune to toxoplasma, you should alert your care provider to fevers, muscle aches, headaches, feeling overly tired, and swollen lymphnodes. These symptoms can last a month or more. Infecting during pregnancy or even up to six months prior to pregnancy can cause infection in an unborn baby.
According to the March of Dimes, three out of ten women who are infected with toxoplasma during pregnancy will pass the infection to the baby. An infection with toxoplasma can cause still birth and preterm birth. About 1 in 10 babies who are born with toxoplasma will have serious complications that include infection in the eyes, enlarged liver and/or spleen, jaundice, or pneumonia. Three out of 10 babies born with toxoplasma will develop problems later in life if they are not treated for toxoplasmosis at birth. These complications include developmental delays, learning disabilities, vision problems, cerebral palsy, seizures or hearing loss.
Pregnant women who develop toxoplasmosis can be treated in pregnancy with antibiotics. Newborns who have the possibility of having been exposed to toxoplasma should be tested at birth and treated with antibiotics. However, prevention should be everyone’s goal.
Never eat undercooked meats especially lamb, pork, venison or moose. Temperature check all your meats to ensure they are heated to 160 degrees F all the way through. Wash your hands with soap and water after handling all raw meats, raw fruits and raw vegetables. Do not touch your face when handling any raw food. Wash all fruits and vegetables. Wear gloves when gardening or handling soil. Avoid changing cat litter. Do not allow your cat out doors where he/she may contract toxoplasma. If you must change the kitty litter, wear gloves and wash your hands after. Stay away from sandboxes, cats often use them as litter boxes. Wash all your counter tops frequently if you have a cat – they can jump up and contaminate counters, tables, etc.
The last topic in this discussion is Fish. There are a lot of mixed messages about fish consumption in pregnancy. Women are told to avoid fish but also told they need the fats from fish for proper brain and eye development for their baby. It is confusing and conflicting advice.
Fish can contain mercury. Mercury is a naturally occurring heavy metal. It is used in manufacturing and has become a significant source of water pollution. Fish in mercury contaminated waters will absorb mercury and are unable to process it back out of their bodies. This means their meat can have mercury in it. Why is this a concern? Well, high levels of mercury can cause neurological damage. The phrase “mad as a hatter” comes from England in the 1700’s when hat makers where exposed to high levels of mercury and it literally made them go insane. So, limiting mercury exposure is important. The amount of mercury in most seafood is small enough that adults can cope without difficulty, however, a developing fetal brain could suffer if exposed.
Fish to avoid are fish known to come from areas of high pollution. Additionally, fish that are predators (fish that eat other fish) should be avoided. The most commonly referenced fish to avoid are shark, tile fish, sword fish, king mackerel. Additionally, it is advised that pregnant women do not consume undercooked or raw fish due to food borne illness concerns.
Pregnant women are encouraged to eat 6-12 oz of low mercury fish per week. If you are harvesting local fish, pay attention to any warnings from local fish and game to avoid any health issues from local fish. Most commercially available fish is safe for consumption. Albacore tuna should be limited to no more than 6 oz per week.
Far too often women are simply told what to do, what food to avoid and never really told why. I hope this helps all expectant parents understand the reasons behind the advice that health care providers give. As always, if you have concerns or questions, call your health care provider.