When pregnant, enjoying a favorite meal like sushi often raises safety questions. The main concern with traditional sushi is raw fish, which carries risks of foodborne illness from bacteria and parasites. When the seafood component is thoroughly cooked, however, the resulting sushi roll is generally safe to consume, provided certain precautions are observed. Cooking eliminates the risk associated with uncooked seafood, allowing pregnant women to access the nutritional benefits of fish without the danger of common pathogens.
Understanding the Safety of Heat Preparation
The safety of cooked sushi relies on heat eliminating biological risks. Raw seafood can harbor harmful microorganisms, such as Listeria monocytogenes bacteria and parasitic worms, which can cause severe illness in pregnant individuals whose immune systems are naturally suppressed. Listeriosis infection can lead to serious complications, including miscarriage or preterm delivery, making the avoidance of raw fish necessary.
Cooking fish to the correct temperature destroys these threats, rendering the seafood safe. Health authorities recommend cooking all seafood to an internal temperature of 145 degrees Fahrenheit (63 degrees Celsius). At this temperature, the flesh becomes opaque and separates easily into flakes, indicating the heat has neutralized pathogens. Fully cooked items, such as shrimp tempura, California rolls made with cooked imitation crab, or rolls containing cooked eel, are acceptable choices because the cooking process provides a reliable barrier against foodborne illnesses.
Beyond the Fish Cross-Contamination and Ingredients
Even when ordering a fully cooked sushi roll, risks can arise from the preparation environment. The most significant residual risk is cross-contamination, which occurs when bacteria from raw seafood are transferred to the cooked ingredients. This transfer happens if a chef uses the same cutting board, knives, or gloves to prepare both raw and cooked items without proper cleaning.
To minimize this hazard, choose restaurants known for high hygiene standards. Specifically request that cooked items be prepared on a clean surface with separate utensils. This precaution ensures that the safety achieved by cooking is not undermined by contact with raw materials.
Beyond the seafood, some auxiliary ingredients in sushi rolls may not be fully cooked or pasteurized and should be avoided. For instance, raw fish roe, such as tobiko or ikura, should be skipped. Similarly, sauces like house-made spicy mayonnaise may contain raw egg, carrying a risk of salmonella. It is best to ask for clarification on ingredients or choose simpler, known-safe additions. Refrigerated smoked fish, such as lox or smoked salmon, is also avoided unless heated until steaming hot, as it can be a source of Listeria bacteria.
Navigating Mercury Levels and Fish Quantity
A concern when consuming fish, raw or cooked, is the presence of methylmercury, a heavy metal that accumulates in seafood. Since cooking does not remove mercury, this risk remains even in cooked sushi. High mercury intake can pass to the developing fetus and potentially affect the neurological system.
To manage this risk, health organizations advise selecting fish species known to be low in mercury and limiting weekly quantity. Large, predatory fish accumulate the highest concentrations of mercury and should be avoided entirely. These include:
- King Mackerel
- Swordfish
- Shark
- Tilefish
- Bigeye and Bluefin tuna (even if used in cooked rolls)
Many types of fish commonly found in cooked sushi are low in mercury and contain beneficial omega-3 fatty acids, which support fetal brain development. Safe choices include salmon, shrimp, pollock, cod, and canned light tuna. Pregnant women should consume 8 to 12 ounces (about two to three servings) of these low-mercury fish per week. Note that white (albacore) tuna should be limited to no more than 6 ounces per week due to its higher mercury content compared to canned light tuna.