Hormonal changes during pregnancy alter the workings of the immune system, and this may increase your risk for certain food-borne illnesses, or food poisoning. In most cases, you and your baby will recover well, as long as you stay hydrated. There are, however, certain bacteria and parasites, including listeria, toxoplasmosis and even salmonella, that can pose specific risks to you and your baby. Talk to your doctor about your diet and risk of infection, as well as any symptoms you may be having.
Listeria is a type of bacteria found in raw milk, soft-ripened cheese, deli meats and fish. When exposed, women who are pregnant are 13 times more likely to become infected with listeria than when not pregnant, according to a December 2014 article published in "Obstetrics and Gynecology." A mother with listeria may only experience mild flulike symptoms, such as fever, aches and diarrhea. For the baby, however, listeria can result in miscarriage, premature delivery and newborn infection that can be fatal. Reduce your risk of exposure by avoiding commonly contaminated foods and making sure your meats are well-cooked.
Raw or under-cooked meats, contaminated fresh foods and exposure to cat feces are potential sources of Toxoplasma gondii, a parasite. A mother with toxoplasmosis will usually have no symptoms, but swollen glands, fever, headache and muscle pain sometimes occur. A baby can become infected even if the mother has no symptoms. According to a review published in "Clinical Infectious Diseases" in August 2008, the effects tend to be most severe when a baby is infected early in pregnancy and least severe when infection occurs near birth. Infants with congenital -- present at birth -- toxoplasmosis may have no symptoms initially, but they can later develop visual problems, slowed physical and mental functioning and other problems.
Salmonella and Other Organisms
Unlike listeria and toxoplasmosis, pregnant women are at no greater risk than the general public of getting sick from salmonella. However, premature delivery, neonatal infection and even stillbirth may occur in a small percentage of cases, according to an April 2010 article in "Canadian Family Physician." To reduce your infection risk, don't eat raw eggs or foods containing raw eggs.
Several other organisms can also cause food poisoning, such as norovirus and E. coli. The main concern with these is dehydration due to vomiting and diarrhea. Be sure to follow food safety guidelines such as not eating raw or undercooked fish or meat, rinsing all raw produce before eating, keeping your kitchen and cooking utensils clean and always washing your hands before and after eating.
When to Call Your Doctor
In cases of food poisoning, the time it takes to get sick after eating contaminated food can vary. Call your doctor immediately when you start having nausea, vomiting or other symptoms in order to help reduce the risk to you and your baby. Be especially alert for the warning signs of dehydration, including scant dark yellow urine, dry mouth, thirst, headache and dizziness.
- American Journal of Reproductive Immunology: The Immune System in Pregnancy: A Unique Complexity
- Obstetrics and Gynecology: Management of Pregnant Women With Presumptive Exposure to Listeria Monocytogenes
- Centers for Disease Control and Prevention: Diagnosis and Management of Foodborne Illness
- Canadian Family Physician: Food-Borne Illness During Pregnancy
- Clinical Infectious Diseases: Management of Toxoplasma Gondii Infection During Pregnancy
- The Merck Manual Professional Addition: Nausea and Vomiting During Early Pregnancy