The concern over eating cold cuts during pregnancy centers on a specific foodborne illness. Cold cuts, also known as deli meats, are ready-to-eat products that are typically consumed without further heating. The primary health risk associated with consuming these refrigerated products is contamination by the bacterium Listeria monocytogenes, which causes a serious infection known as Listeriosis. Avoiding or properly preparing these meats is a precautionary measure taken to protect both the pregnant person and the developing fetus from this potentially devastating illness.
Understanding Listeriosis: The Primary Threat
The organism responsible for the concern is Listeria monocytogenes, a type of bacteria unique because it can multiply even in cold temperatures, including inside a refrigerator. This capability makes it a specific threat in ready-to-eat, refrigerated foods like deli meats that are often stored for long periods. Contamination of cold cuts frequently occurs after the meat has been cooked but before packaging, often during the slicing process on deli equipment or through poor handling.
Pregnant individuals are uniquely susceptible to Listeriosis, being about 10 to 20 times more likely to contract the infection compared to the general healthy adult population. This heightened vulnerability is due to the natural immune system suppression that occurs during pregnancy. While Listeriosis is rare overall, the severity of the illness in pregnancy is why avoidance is emphasized. The infection begins with the consumption of contaminated food, where the bacteria invade the intestine and can then travel through the bloodstream to spread to other organs.
Fetal and Neonatal Risks from Infection
The greatest danger of Listeriosis lies in its consequences for the unborn baby, even if the pregnant person experiences only mild symptoms. Once the bacteria enters the bloodstream, it can cross the placental barrier, directly infecting the fetus. This transplacental transmission can occur at any point during the pregnancy, but the effects are often most severe in the second and third trimesters.
Infection of the fetus can lead to severe adverse pregnancy outcomes, including miscarriage, premature delivery, or stillbirth. The rate of fetal loss or neonatal death in cases of invasive Listeriosis is reported to be around 29 percent. If the baby is born alive, they may suffer from severe neonatal infections, such as sepsis or meningitis. The symptoms in the pregnant person are often non-specific, resembling a mild flu with fever, muscle aches, and fatigue. This mild presentation makes the infection difficult to detect in the mother, meaning the fetus can be silently infected until serious complications arise.
Preparation Methods for Safe Consumption
Cold cuts do not need to be entirely eliminated from the diet if they are prepared properly, as heat can effectively destroy the bacteria. The risk of Listeriosis is eliminated when the meat is heated to a minimum internal temperature of 165°F, or until it is visibly steaming hot.
For example, if a pregnant person wishes to have a deli meat sandwich, the meat must be thoroughly heated until it reaches the necessary temperature. The entire portion of meat must be hot, as microwaves can sometimes heat unevenly, leaving cold spots where bacteria can survive. Once heated, the meat should be consumed immediately and not allowed to cool back down before eating. Using cold cuts as an ingredient in cooked dishes, such as casseroles or hot paninis, is generally considered safe, provided the entire dish reaches the required high temperature. Freezing deli meats does not kill Listeria; it only stops the growth of the bacteria.
Other Foods to Avoid During Pregnancy
To minimize the risk of foodborne illness during pregnancy, cold cuts are not the only food requiring caution. Other ready-to-eat foods that share a similar risk profile for Listeria contamination should also be avoided or properly prepared.
- Unpasteurized soft cheeses, such as Brie, Camembert, and blue-veined varieties, which can harbor the bacteria because of their higher moisture content.
- Refrigerated pâtés and meat spreads, unless they are canned and shelf-stable, as they are stored cold, allowing for potential Listeria growth.
- Refrigerated smoked seafood, such as lox or gravlax, unless it is cooked until steaming hot, such as when used in a hot casserole.
- Raw sprouts, including alfalfa, clover, and radish sprouts, which can be contaminated with Salmonella or E. coli due to bacteria introduced during the sprouting process.
- Unpasteurized milk and unpasteurized juices or ciders, as the lack of pasteurization means any harmful bacteria may not have been destroyed.