The advice to avoid deli meat during pregnancy stems from the risk of contracting listeriosis. This serious foodborne illness is caused by a bacterium that poses a significant threat to the health of the developing baby and the pregnant person. This restriction is a direct precautionary measure against the specific danger presented by this pathogen in ready-to-eat products.
The Specific Threat: Listeria Monocytogenes
The microorganism responsible is Listeria monocytogenes, a bacterium found widely in the environment, including soil and water. Unlike many other foodborne pathogens, L. monocytogenes is psychrotolerant, meaning it can survive and multiply in cold, refrigerated temperatures as low as 32°F (0°C). This adaptation allows it to function even in chilled conditions.
While listeriosis is relatively rare, it is one of the most lethal foodborne illnesses. Healthy, non-pregnant adults who contract the bacteria may experience only mild, flu-like symptoms. However, for individuals with weakened immune systems, such as pregnant people, the infection can become invasive and severe.
Why Deli Meat Poses a Risk
Deli meats, including cold cuts and dry sausages, are considered high-risk foods because they are ready-to-eat (RTE) and consumed without further cooking. While the initial manufacturing process kills bacteria, post-processing contamination can occur. This happens when the meat comes into contact with surfaces or equipment that harbor the bacteria, such as slicers or preparation tables.
The contamination risk is particularly high with meats sliced at a retail deli counter, where slicers may spread Listeria between various products. Since the meat is stored under refrigeration and eaten cold, the psychrotolerant bacteria have an extended window to multiply to dangerous levels. The long refrigerated shelf life and the high moisture content of deli meats further facilitate the growth of L. monocytogenes.
How Listeriosis Affects Pregnancy
Pregnant individuals are 10 to 20 times more likely to contract listeriosis than the general healthy population. This increased susceptibility occurs because the immune system undergoes natural suppression during pregnancy, making it harder to fight off the infection. Once infected, the bacteria can easily cross the placental barrier, leading to severe consequences for the fetus.
The infection may cause only a mild, flu-like illness in the mother, sometimes with no symptoms at all. Despite the mother’s mild presentation, the bacteria’s passage to the fetus can result in severe outcomes. Listeriosis is associated with an increased risk of miscarriage, stillbirth, premature delivery, and life-threatening infection of the newborn.
Newborns infected with Listeria may develop severe conditions such as sepsis or meningitis. These neonatal infections can cause long-term health issues, including developmental delays or paralysis. The high mortality rate associated with invasive listeriosis underscores the seriousness of this food safety concern during gestation.
Safe Ways to Consume Deli Meats
The most effective way to eliminate the risk of Listeria in deli meats is through heat treatment. The bacteria are destroyed when the meat reaches a specific internal temperature. Pregnant people can safely consume deli meats, including cold cuts and hot dogs, if they are heated to an internal temperature of 165°F (74°C).
The meat must be visibly steaming hot throughout to ensure the temperature threshold has been met. Heating methods like an oven or stovetop are generally more reliable than a microwave, which can leave cold spots where bacteria may survive. After heating, the meat can be eaten immediately or allowed to cool. To prevent recontamination, heated deli meat should be handled with clean utensils and any leftovers discarded promptly.