Listeriosis and Pregnancy: What is Your Risk?

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Safe Food Handling for a Healthy Pregnancy

When you're expecting, it's natural to be concerned about your health and that of your unborn baby. Maintaining a healthful diet, drinking plenty of liquids, and taking prenatal vitamins are all important for the health of the expectant mother and her baby. Food safety is also very important. This information will help you make safe decisions when selecting and preparing food for yourself and/or your family.

Sometimes, what we eat can make us sick. Food contaminated by harmful bacteria can cause serious illness. One type of bacteria, Listeria monocytogenes ( pronounced lis-TIR-ee-ya mon-o-si-TAH-gin-eez), can cause an illness called listeriosis. The Centers for Disease Control and Prevention ( CDC) estimates that 2,500 people become seriously ill with listeriosis each year in the United States. Of these, one in five die from the disease. Listeriosis can be particularly dangerous for pregnant women and their unborn babies. Foodborne illness caused by Listeria in pregnant women can result in premature delivery, miscarriage, fetal death, and severe illness or death of a newborn from the infection.

What is Listeria?

Listeria is a type of bacteria found everywhere in soil and ground water and on plants. Animals and people can carry Listeria in their bodies without becoming sick. Despite being so widespread, most infections in humans result from eating contaminated foods.

Most people are not at increased risk for listeriosis. However, there are some people who are considered at risk because they are more susceptible to listeriosis. In addition to pregnant women and their unborn babies and newborns, other at-risk groups include older adults and people with weakened immune systems caused by cancer treatments, AIDS, diabetes, kidney disease, etc. By carefully following food safety precautions, persons at risk for listeriosis can substantially reduce their chances of becoming ill.

Why is listeriosis especially dangerous for me and my child?

Hormonal changes during pregnancy have an effect on the mother's immune system that lead to an increased susceptibility to listeriosis in the mother. According to the CDC, pregnant women are about 20 times more likely than other healthy adults to get listeriosis. In fact, about one-third of listeriosis cases happen during pregnancy. Listeriosis can be transmitted to the fetus through the placenta even if the mother is not showing signs of illness. This can lead to premature delivery, miscarriage, stillbirth, or serious health problems for her newborn.

Is Listeria transmitted from the mother to the baby through breast milk?


While there is a theoretical possibility that Listeria monocytogenes could be transmitted via mother's milk, this has never been proven.

How will I know if I have listeriosis?

Because the symptoms of listeriosis can take a few days or even weeks to appear and can be mild, you may not even know you have it. This is why it's very important to take appropriate food safety precautions during pregnancy.

In pregnant women, listeriosis may cause flu-like symptoms with the sudden onset of fever, chills, muscle aches, and sometimes diarrhea or upset stomach. The severity of the symptoms may vary. If the infection spreads to the nervous system, the symptoms may include headache, stiff neck, confusion, loss of balance, or convulsions. Consult your doctor or healthcare provider if you have these symptoms. A blood test can be performed to find out if your symptoms are caused by listeriosis.

What is the treatment for listeriosis?

During pregnancy, antibiotics are given to treat listeriosis in the mother. In most cases, the antibiotics also prevent infection of the fetus or newborn. Antibiotics are also given to babies who are born with listeriosis.

What steps can I take to prevent listeriosis?

USDA's Food Safety and Inspection Service (FSIS) and the U. S. Food and Drug Administration (FDA) provide the following advice for pregnant women and all at-risk consumers:

  • Do not eat hot dogs, luncheon meats, or deli meats unless they are reheated until steaming hot.

  • Do not eat soft cheeses such as feta, Brie, Camembert, blue-veined cheeses, and Mexican-style cheeses such as "queso blanco fresco." Hard cheeses, semi-soft cheeses such as mozzarella, pasteurized processed cheese slices and spreads, cream cheese, and cottage cheese can be safely consumed.

  • Do not eat refrigerated p