Fresh mozzarella is a popular, mild, and creamy cheese enjoyed in many dishes, but its safety during pregnancy often causes concern. Expectant mothers must carefully evaluate the foods they eat. While many soft cheeses pose a risk, the safety of fresh mozzarella depends entirely on a single factor that determines its potential to harbor harmful bacteria. Navigating food guidelines during pregnancy requires understanding this distinction.
Pasteurized Versus Unpasteurized
The defining factor that determines whether fresh mozzarella is safe for consumption is whether the milk used in its production was pasteurized. Pasteurization involves heating milk to a specific high temperature for a set amount of time. This thermal treatment is highly effective at destroying harmful microorganisms, including bacteria and pathogens, which may naturally be present in raw milk.
Fresh mozzarella made from pasteurized milk is considered safe for pregnant individuals because the heat treatment eliminates the risk of bacterial contamination. This includes the pre-packaged, vacuum-sealed balls of fresh mozzarella commonly found in grocery stores. Conversely, cheese produced using unpasteurized, or raw, milk carries a significantly higher risk of containing hazardous bacteria.
Raw milk has not undergone the heat treatment of pasteurization, allowing any bacteria present to remain viable. Artisan varieties, especially imported mozzarella di bufala or those from small, local dairies, are more likely to be made with unpasteurized milk. If a cheese label does not explicitly state that the milk was pasteurized, it should be avoided by pregnant individuals.
Understanding the Listeria Risk
The primary reason to avoid unpasteurized soft cheeses is the potential presence of the bacterium Listeria monocytogenes. This organism causes Listeriosis, a rare but serious foodborne illness. Pregnant women are approximately 10 times more likely to contract Listeriosis compared to the general healthy adult population because hormonal changes can temporarily lower their immune response.
In adults, the symptoms of Listeriosis are often mild, resembling a flu-like illness with fever, muscle aches, or digestive issues. However, the pathogen can cross the placenta and seriously affect the developing fetus. Listeriosis infection during pregnancy is associated with severe outcomes, including miscarriage, stillbirth, and premature delivery.
Consumer Safety Guidelines
To enjoy fresh mozzarella safely, always check the product label for the word “pasteurized” or “made with pasteurized milk.” This verification step is the most reliable way to ensure the cheese is safe to consume, whether eaten cold or cooked. If purchasing fresh mozzarella from a deli counter, farmer’s market, or an imported variety without clear labeling, assume it is unpasteurized and avoid consumption.
Unpasteurized soft cheeses, including mozzarella, can be made safer if they are thoroughly cooked. Heating the cheese to a high internal temperature, typically until it is steaming hot throughout, effectively kills Listeria monocytogenes. For example, fresh mozzarella used on a pizza or baked pasta dish is generally safe because it reaches a temperature of at least 160 degrees Fahrenheit. However, relying on pasteurization status is the primary and preferred method for determining safety.