Food Poisoning During Pregnancy

Topic Overview

A balanced, nutritious diet during your pregnancy is important to maintain your health and nourish your fetus. When making your food choices, you generally are able to eat the foods you usually eat. But because some types of food poisoning pose a greater risk to you and your fetus, you should take a few extra precautions when you choose and prepare your foods.

Listeriosis

Listeriosis is caused by Listeria monocytogenes, a bacterium found in soil and water. It can be found on vegetables, meats, and dairy products as well as in processed foods such as soft cheeses and in cold cuts. Although the bacteria are of little danger to healthy people, in pregnant women the infection can result in premature delivery, serious infection of the newborn, or even stillbirth.

Symptoms of listeriosis include fever, muscle aches, and sometimes nausea or diarrhea. In some cases, headache, stiff neck, confusion, loss of balance, or convulsions can occur. Pregnant women who are infected may experience only a mild, flu-like illness.

If you are pregnant and get listeriosis, taking antibiotics can often prevent infection of the fetus or newborn. Babies who have listeriosis receive the same antibiotics as adults, although a combination of antibiotics is often used until doctors are certain of the diagnosis.

If you are pregnant:

• Do not eat hot dogs, luncheon meats, or deli meats, unless they are reheated until steaming hot.
• Do not eat soft cheeses unless the label states they are made from pasteurized milk. Common cheeses typically made with unpasteurized milk-such as feta, Brie, Camembert, blue-veined cheeses, and Mexican-style cheeses such as "queso blanco fresco"-can cause listeriosis. Hard cheeses and semisoft cheeses such as mozzarella along with pasteurized processed cheese slices and spreads, cream cheese, and cottage cheese are safe to eat.
• Do not eat refrigerated pâté or meat spreads. But you can eat these foods if they are canned.
• Do not eat refrigerated smoked seafood unless it is an ingredient in a cooked dish such as a casserole. Examples of refrigerated smoked seafood include salmon, trout, whitefish, cod, tuna, and mackerel. You may eat canned fish such as salmon and tuna or shelf-stable smoked seafood.
• Do not drink raw (unpasteurized) milk or eat foods that contain unpasteurized milk.
• Avoid eating salads made in a store, such as ham, chicken, egg, tuna, or seafood salads.

Toxoplasmosis

Toxoplasmosis is caused by the parasite Toxoplasma gondii. A pregnant woman can give toxoplasmosis to her fetus. Fetal toxoplasmosis can cause miscarriage, stillbirth, and birth defects.

You can acquire the parasite by accidentally swallowing Toxoplasma gondii eggs from soil or other contaminated surfaces. This can happen by putting your hands to your mouth after gardening, cleaning a cat's litter box, or touching anything that has come into contact with cat feces.

Toxoplasmosis often has no symptoms, or the symptoms are flu-like. You may have swollen lymph glands or muscle aches and pains that last for a few days to several weeks.

If you:

• Are planning to become pregnant, consider being tested for Toxoplasma gondii. If the test is positive, it means that you have already been infected at some time in your life and you probably do not have to worry about giving the infection to your future baby (discuss this with your doctor). If the test is negative, take precautions to avoid infection.
• If you are pregnant, you and your doctor should discuss your chance of getting toxoplasmosis. Your doctor may order a blood sample for testing.

If you are diagnosed with toxoplasmosis during your pregnancy, you will be treated with antibiotics. If further testing shows that your fetus is infected, you will be given antibiotics that are known to reduce the impact of toxoplasmosis on the fetus.

To help prevent toxoplasmosis:

• Avoid cat feces, in both the home and the garden.
  • If you have a cat and you are either pregnant or planning to become pregnant soon, have someone else clean the cat litter box. If you must clean the box yourself, do it daily. Wear gloves and a face mask, and wash your hands afterward.
  • Make a habit of washing any table or counter surfaces that a cat may have walked across.
  • Consider keeping your cat indoors. A cat who goes outdoors is likely to become infected with Toxoplasma gondii by eating infected birds or rodents. (Eating indoor mice also poses a risk.)
  • When gardening or handling soil, wear gloves and wash your hands afterward.
  • Wash all foods that could have had contact with cat feces, including commercial fruits and vegetables.
• Eat only well-cooked or previously frozen meat. Avoid dried meats. Sustained high or low temperatures are needed to kill Toxoplasma gondii in meat.
• Carefully wash your hands and all utensils after preparing raw meat, poultry, seafood, fruits, or vegetables.
• Avoid untreated drinking water. This is a concern when you are in the wilderness or are traveling to developing countries where drinking water is not treated.

Other food poisoning

Pregnant women may become much more ill from food poisoning than other people, so it is important that you prevent food poisoning in your home by taking precautions when preparing and storing foods. Perishable foods, such as eggs, meats, poultry, fish, shellfish, milk, and milk products, should be treated with extra care.

The U.S. Department of Agriculture recommends the following steps to prevent food poisoning.

• Shop safely. Bag raw meat, poultry, or fish separately from other food items. Drive home immediately after finishing your shopping so that you can store all foods properly.
• Prepare foods safely. Wash your hands before and after handling food. Also wash them after using the bathroom or changing diapers. Wash fresh fruits and vegetables by rinsing them well with running water. If possible, use two cutting boards-one for fresh produce and the other for raw meat, poultry, and seafood. Otherwise, be sure to wash the cutting board with hot, soapy water between each use. You can also wash your knives and cutting boards in the dishwasher to disinfect them.
• Store foods safely. Cook, refrigerate, or freeze meat, poultry, eggs, fish, and ready-to-eat foods within 2 hours. Make sure your refrigerator is set at 40°F (4°C) or colder.
• Cook foods safely. Use a clean meat thermometer to determine whether foods are cooked to a safe temperature. Reheat leftovers to at least 165°F (74°C). Do not eat undercooked hamburger, and be aware of the risk of food poisoning from raw fish (including sushi), clams, and oysters.
• Serve foods safely. Keep cooked hot foods hot [140°F (60°C) or above] and cold foods cold [40°F (4°C) or below].
• Follow labels on food packaging. Food packaging labels provide information about when to use the food and how to store it. Reading food labels and following safety instructions will reduce your chances of becoming ill with food poisoning.
• When in doubt, throw it out. If you are not sure whether a food is safe, don't eat it. Reheating food that is contaminated will not make it safe. Don't taste suspicious food. It may smell and look fine but still may not be safe to eat.

Pay particular attention to food preparation and storage during warmer months when food is often served outside. Bacteria grow faster in warmer weather, so food can spoil more quickly and possibly cause illness. Do not leave food outdoors for more than 1 hour if the temperature is above 90°F (32°C), and never leave it outdoors for more than 2 hours.

For more information, see the topics Toxoplasmosis During Pregnancy, E. Coli Infection, and Food Poisoning and Safe Food Handling.