Listeria and Pregnancy: What Is It, Symptoms, and How to Avoid Infection

Listeria is one of those scary words during pregnancy that you’ve heard but may not be exactly sure what it is. You probably know the basics about what foods you should not eat to avoid infection but what is listeria, exactly? And why is listeria so dangerous for pregnant women and their unborn babies? 

These are all excellent questions and a great place to begin when educating yourself about these dangerous bacteria. Here are the basics about listeria and why it is crucial that you take steps to avoid these bacteria while pregnant. 

What is it?

Listeria is a form of bacteria that can be found in uncooked vegetables, fruits and meats, unpasteurized milk and cheeses and processed foods. Listeria moncytogenese can originate in water and soil and animals can also act as carriers for the bacteria. When food comes in contact with listeria, it is considered contaminated and the bacteria can only be killed by cooking the food to the proper temperature or through pasteurization. 

Why is there an increased risk for pregnant women?

When a person becomes ill from the bacteria listeria, they are said to have listeriosis. While this is a rare condition, pregnant women are approximately 10-20 times more susceptible to infection than non-pregnant adults. Contracting listeriosis during pregnancy can result in serious complications for both mom and baby including miscarriage, premature delivery, infection to the newborn, and in extreme cases fetal or maternal death. As many as 1/5 cases of listeria infection in pregnant women result in stillbirth or neonatal death.

What are the symptoms of listeria infection?

Symptoms of listeriosis can begin as early as several days after exposure or as late as one month later. They may include:

• Mild flu like symptoms
• Headaches
• Fever
• Vomiting or diarrhea
• Muscle pain

Fortunately with early detection, an aggressive antibiotic regimen can help prevent the infection from crossing the placental barrier and infecting the baby. This can greatly reduce the chances of severe complications like miscarriage or stillbirth. If you suspect you may have become infected with listeria, contact your doctor immediately who can perform a blood test to check for the presence of the bacteria.

How can I avoid listeria infection while pregnant?

With extra attention to what you eat and proper food safety and handling, you can greatly reduce your risk of coming in contact with the bacteria listeria while pregnant. Here are some tips to preventing infection during pregnancy and keeping you and your baby healthy:

• Skip deli meats and hot dogs unless reheated to steaming (160 degrees F)
• Avoid soft cheeses that may not be pasteurized such as Brie, feta, goat cheese, Camembert, 
• Mexican cheeses (queso fresco, quesos blanco and panela), and blue-veined cheeses. Hard cheeses and semi-soft cheeses like mozzarella are fine, as are cream cheese and cottage cheese.
• Do not eat pate or other cold meat spreads
• Do not eat refrigerated smoked salmon unless it has been cooked in a dish.
• Keep food prep areas clean
• Wash your hands before eating or handling food
• Cook foods to their proper internal temperatures
• Keep your refrigerator clean and set at 40 degrees or less
• Wash fruits and veggies thoroughly before eating
• Avoid raw or uncooked meats and seafood
• Refrigerate and freeze leftovers promptly.

For more foods to avoid during pregnancy, check out this article. 

Although it is important to take measures to avoid listeria during pregnancy due to the potential for serious complications, remember that instances of listeriosis are extremely rare. In the US, approximately 1,700 people each year become infected with the illness of which only 17 percent are pregnant women. With a healthy, pregnancy conscious diet and safe food handling practices, there is no need to be fearful of listeria infection. Listeriosis is fortunately very preventable in most cases. For questions about maternal and fetal health, natural birth or any and all pregnancy related topics, contact Health Foundations for a free consultation with a midwife and for a tour of our Birth Center.