Food-borne bacterial infections are one potentially preventable cause of miscarriage and stillbirths, so it is wise to be vigilant about what you eat during pregnancy in order to reduce your risk of food poisoning. The bacterial strains most associated with miscarriage are Listeria, Salmonella, Toxoplasma, and E. coli. No method of avoiding food poisoning is ever entirely foolproof, but avoiding the foods at highest risk of harboring these bacteria will go a long way toward reducing your risk of miscarriage from food poisoning.
Listeria species are the bacteria that cause the disease listeriosis. In non-pregnant people, the most common signs are abdominal pain, nausea/vomiting, diarrhea and fever. In pregnant women, a non-specific flu-like illness is the most common sign. Symptoms may include fever, chills, body aches and malaise. However, pregnant women are more susceptible to complicated infections, and in the U.S., Listeria infection during pregnancy occurs most often in the third trimester, so is more likely to be a cause of a stillbirth than an early miscarriage.
Foods that may harbor Listeria include:
- Unpastereurized milk and cheeses
- Imported soft cheeses, such as Brie, Gorgonzola, feta, and Roquefort (non-imported soft cheese made from pasteurized milk should be safe)
- Deli meats
- Refrigerated, smoked seafood eaten on its own (not as an ingredient in a well-cooked meal)
- Refrigerated pate or meat spreads
Salmonella bacteria species cause a disorder called Salmonella enterocolitis, also called Salmonellosis. Symptoms include diarrhea, abdominal pain, nausea, vomiting, and fever or chills. The primary culprits are undercooked poultry products:
Cook all eggs thoroughly during pregnancy in order to best reduce risks; one survey in the early 1990s found pathogenic Salmonella in 24% of eggs sampled from U.S. hen houses. Incidence in more recent surveys has been lower, but cooking eggs carefully is a good precaution.
The bacterium Toxoplasma gondii is the culprit in the disease toxoplasmosis. People tend to associate toxoplasmosis with cat litter boxes, but it can also be a food-borne infection. Symptoms of toxoplasmosis are enlarged lymph nodes, muscle pain, headache, mild fever, and sore throat; the disease is often confused with the flu.
The major food to avoid is:
- Undercooked raw meat
Reports of Escherischia coli poisoning tend to hit the media now and then, and certain forms of the bacteria do pose a risk for miscarriage. (E. coli is also a normal inhabitant of the human intestinal tract; only certain species cause problems.) Poisoning with E. coli causes the disorder E. coli enteritis. Symptoms include abdominal pain, diarrhea, fever, gas, cramping, and rarely vomiting.
Foods that pose risk include:
- Undercooked, unsanitary food (be careful in restaurants)
- Contaminated water in certain countries
- Unwashed fruits and vegetables
American Pregnancy Association, "Foods to Avoid During Pregnancy." Nov 2007. Accessed 9 Jan 2008.
Ebel, Eric D., Michael J. David, and John Mason. "Occurrence of Salmonella enteritidis in the U.S. Commercial Egg Industry: Report on a National Spent Hen Survey.." Avian Diseases 1992. Accessed 9 Jan 2008.