Pregnancy comes with a long list of don’ts, especially regarding what you shouldn’t eat: Don’t eat cheese. Don’t eat sushi. Don’t eat raw meat. Trying to make healthy food choices may become dizzying and confusing when you’re newly pregnant — and even if you’re already a mom!
But there are reasons behind food restrictions during pregnancy.
Pregnancy is a time in your life when your body changes to accommodate your growing baby. You begin to breathe more deeply, and your heart beats stronger and faster. Your immune system also undergoes changes during pregnancy that result in some infections becoming harder for your body to fight off.
Listeria and Pregnancy
The goal of food-related don’ts is to help prevent exposure to food-related infections that are easier to contract in pregnancy. One of the more serious infections that can affect pregnant women is Listeria. Pregnant women make up one-third of all Listeria cases in the U.S. It is easiest to get Listeria in the third trimester, especially if you’re expecting twins or triplets. The third trimester is when the immune system changes most, so the later in pregnancy you are, the more at risk you are.
Listeria is a bacterium found in certain foods, which is why your healthcare provider gives you a list of foods to avoid during pregnancy. The biggest culprits follow.
• Hot dogs, luncheon meats and deli meats, unless they are reheated until steaming hot. Using a microwave is not recommended, as uneven heating often occurs.
• Premade salads containing eggs, tuna, ham, chicken or seafood.
• Soft cheeses, unless the label specifically states that they were made with pasteurized milk. Examples of soft cheeses include Brie, Camembert, feta, blue cheese and other blue-veined cheeses, or Mexican-style cheeses such as queso blanco, queso fresco and queso panela.
• Meat spreads and refrigerated pâtés. Canned and shelf-stable meats are safe to eat.
• Refrigerated smoked seafood. Canned and shelf-stable smoked seafood is safe to eat.
The Food Safety and Inspection Service (FSIS) and the Centers for Disease Control and Prevention (CDC) have recommended simple ways to prevent Listeria, listed below.
• Do not drink or consume food that contains raw (unpasteurized) milk.
• Wash raw vegetables and fruits thoroughly before consuming them.
• Keep the temperature of the refrigerator at 40° F (4.4° C) or lower and the freezer at 0° F (-17.8° C) or cooler.
• Eat perishable, ready-to-eat or pre-cooked food as soon as possible.
• In your refrigerator, separate uncooked meat and poultry from vegetables and other food that will not be cooked.
• After handling uncooked food, wash your hands, as well as all knives and cutting boards you have just used.
• Cook all foods thoroughly to their recommended temperature: ground beef should be 160° F (71° C); chicken, 170° F (77° C); turkey, 180° F (82° C); and pork, 160° F (71° C).
Over the years, Listeria outbreaks have made headlines in the news. Listeria causes a gastrointestinal illness, with nausea, vomiting and watery diarrhea. The key symptom is a fever, which is usually associated with muscle aches and a headache. If you are pregnant and you have eaten a food involved in a Listeria outbreak, you should monitor yourself. There are no tests to determine if you were exposed; the only tests available are performed if you start showing signs of the infection. If you develop a fever or diarrhea, you should call your provider immediately.
Listeria during pregnancy can be treated with antibiotics. However, even with early treatment, Listeria can infect your baby during pregnancy, resulting in your baby becoming ill or even dying. It is for this reason that the prevention of Listeria is so important, and you should avoid all the foods that put you at risk for the infection.
Other food-related bacteria that can cause vomiting and diarrhea are Escherichia coli, Shigella, Vibrio and Campylobacter. A few of these organisms can also infect your baby. A rare cause of GI illness is toxoplasmosis, which is transmitted by eating undercooked meat. Cat feces can also spread toxoplasmosis, which is why pregnant women with a cat should not clean the litter box. Toxoplasmosis causes a serious infection in newborns. It is important to prevent these bacteria during pregnancy, using the same recommendations for avoiding Listeria, listed above. Be sure to discuss any questions or concerns you may have with your provider.
Remember, practicing good food-preparation hygiene and avoiding high-risk foods have an essential purpose: to keep you and your baby healthy.
Shaunna L. Escobar, MD, MPH, CPH, is a Resident Physician in Family Medicine at St. Vincent’s HealthCare in Jacksonville, FL. She is a full-spectrum Family Medicine physician, providing care to patients of all ages, and to obstetrics patients.