String cheese is a popular snack made from low-moisture mozzarella, known for its characteristic stringy texture. For pregnant women, string cheese is generally safe to consume, provided it was manufactured using pasteurized milk. As a source of protein and calcium, it can be a beneficial part of the diet during pregnancy, if food safety precautions are observed.
The Critical Factor: Pasteurization
Pasteurization is the most important safety measure for dairy products consumed during pregnancy. This technique involves heating the milk to a specific temperature for a set duration, effectively eliminating harmful bacteria before the cheese-making process begins. This thermal treatment is highly effective at killing common pathogens.
Nearly all commercially produced string cheese in the United States is made with pasteurized milk. The heat treatment destroys microorganisms without significantly altering the milk’s nutritional profile. Cheeses made from unpasteurized, or raw, milk have a significantly higher risk of containing bacteria that could cause foodborne illness. Pregnant individuals should always look for the “pasteurized” designation on the label.
Understanding Listeria Risk
The primary pathogen pasteurization mitigates in soft cheeses is Listeria monocytogenes, the bacterium responsible for listeriosis. While rare in the general population, pregnant women are approximately ten times more likely to contract this infection. The concern is the potential for the infection to cross the placenta.
Listeriosis can lead to serious adverse outcomes for the developing fetus or newborn, including miscarriage, stillbirth, premature delivery, and severe infection. Unlike many other bacteria, Listeria can grow slowly even under refrigeration, posing a threat in improperly handled or unpasteurized dairy. Properly pasteurized and safely stored string cheese presents a very low risk of this bacterial contamination.
Safe Selection and Handling Guidelines
Even with pasteurized products, pregnant consumers must follow strict guidelines for selection and storage to maintain food safety. The primary step is to check the packaging for the word “pasteurized” to confirm the milk source. If the cheese is from an artisanal source or a deli counter and the pasteurization status is unknown, it should be avoided.
Once purchased, string cheese must be refrigerated promptly and stored at or below 40°F (4°C) to inhibit bacterial growth. It is important to adhere to the expiration or “best by” date printed on the packaging and discard any cheese that has passed this date. Consumers should also inspect the packaging for any signs of damage or improper storage at the store. String cheese should not be left out at room temperature for extended periods, as this allows contamination to multiply rapidly.