Eating raw fish while pregnant increases your risk of foodborne infections that can cause serious pregnancy complications, including miscarriage, premature delivery, and stillbirth. The risk from any single piece of sushi is low in absolute terms, but pregnancy makes you significantly more vulnerable to certain pathogens, and the consequences are more severe than they would be otherwise.
Why Pregnancy Makes Raw Fish Riskier
Your immune system naturally dials back during pregnancy to avoid rejecting the fetus. That shift makes you roughly 10 times more likely than other healthy adults to develop listeriosis, the most dangerous foodborne infection linked to raw and undercooked seafood. About 1 in 6 of all listeria cases in the U.S. occur in pregnant women, even though they represent a small fraction of the population.
The absolute numbers are reassuring: roughly 1 in 25,000 pregnant women in the United States develop a listeria infection each year. But the consequences when it does happen are severe. Listeriosis during pregnancy can cause miscarriage, stillbirth, premature labor, low birth weight, and life-threatening infection in the newborn. You might feel only mild flu-like symptoms, or nothing at all, while the infection crosses the placenta and affects the baby.
The Three Main Threats in Raw Fish
Bacteria
Listeria is the headline concern, but it’s not the only one. Vibrio bacteria, commonly found in raw shellfish, can cause anything from mild stomach pain to severe diarrhea, vomiting, and fever. The infection itself may not directly harm the fetus, but the dehydration from prolonged vomiting and diarrhea is a real concern during pregnancy. Salmonella follows a similar pattern: the primary danger is the cascading effect of a severe gastrointestinal illness on a pregnant body rather than direct fetal infection.
Parasites
Raw fish can carry parasites like anisakis, a roundworm found in many ocean fish species. In anyone, anisakis causes intense abdominal pain, nausea, vomiting, and allergic reactions. In pregnant women specifically, parasitic infections raise the risk of anemia and weakened immunity, which can lead to intrauterine growth restriction (a baby that’s smaller than expected) and preterm delivery.
Mercury
Mercury isn’t unique to raw fish, but it’s worth noting because many popular sushi fish are high-mercury species. Bigeye tuna, one of the most common sushi-grade tunas, contains an average of 0.689 parts per million of mercury. That’s high enough that the FDA lists it as a “Choice to Avoid” during pregnancy. Yellowfin tuna comes in at 0.354 ppm. By contrast, salmon averages just 0.022 ppm. Mercury accumulates in the baby’s developing nervous system, so the concern applies whether the fish is raw or cooked.
What About Restaurant-Grade Sushi?
In many countries, fish sold for raw consumption must be flash-frozen before serving. The FDA requires freezing at -4°F (-20°C) for 7 days, or at -31°F (-35°C) until solid followed by 15 to 24 hours of storage at those temperatures. This process kills parasites effectively. It does not, however, eliminate bacteria like listeria or vibrio. So even high-quality sushi from a reputable restaurant still carries some bacterial risk.
The UK’s NHS takes a slightly more permissive stance than the FDA. It allows sushi made with previously frozen raw fish (since freezing handles parasites) but advises pregnant women to avoid raw shellfish entirely and to skip cold-smoked or cured fish like smoked salmon unless it’s been heated until steaming hot. The reasoning: cold-smoked fish is a known listeria risk, and raw shellfish can harbor bacteria, viruses, and toxins that cooking destroys.
The FDA’s guidance is more conservative. It recommends that pregnant women eat 8 to 12 ounces of cooked seafood per week, choosing lower-mercury species, and avoid raw or undercooked fish altogether.
How to Tell Food Poisoning From Morning Sickness
If you ate raw fish and now feel unwell, the timing and symptoms matter. Morning sickness tends to build gradually over weeks, peaks around weeks 8 to 12, and rarely involves fever. Food poisoning typically comes on within hours to a couple of days after eating contaminated food and brings a distinct combination of symptoms: diarrhea, vomiting, stomach cramps, and sometimes fever or chills.
Fever is the key red flag. If you’re pregnant and develop a fever along with feeling more tired and achy than usual, that pattern is consistent with listeriosis and warrants a call to your doctor right away. Listeria has an unusually long incubation period compared to other foodborne bacteria. Symptoms can appear anywhere from a few days to several weeks after exposure, which makes it easy to forget the meal that caused it.
If You Already Ate Raw Fish
A single serving of sushi is unlikely to cause harm. The absolute risk of contracting listeriosis from any given meal is very small, and most raw fish served at restaurants in the U.S. and UK has been handled under food safety protocols that reduce (but don’t eliminate) the danger. That said, if you develop fever, muscle aches, nausea, or diarrhea in the days or weeks following, don’t dismiss the symptoms as pregnancy-related fatigue. Mention the raw fish to your healthcare provider so they can test for the right infections.
Safer Ways to Satisfy a Sushi Craving
You don’t have to skip the sushi restaurant entirely. Cooked seafood rolls are a straightforward swap: shrimp tempura, crab, cooked octopus, and seared or fully cooked tuna all eliminate the raw fish risk while still giving you the protein and omega-3 fatty acids that support fetal brain development. Vegetable rolls with avocado, cucumber, or sweet potato work too, though they won’t deliver the same omega-3 benefit.
If you’re choosing cooked fish (at a restaurant or at home), the FDA recommends sticking to 2 to 3 servings per week from lower-mercury species. One serving during pregnancy is 4 ounces. Salmon is one of the best options: extremely low in mercury at 0.022 ppm and rich in omega-3 fatty acids. Shrimp, tilapia, and pollock also fall into the “Best Choices” category. Avoid bigeye tuna, swordfish, shark, and marlin regardless of how they’re prepared.
Tamagoyaki (Japanese omelet) nigiri and inari (seasoned tofu pockets filled with rice) round out the menu without any seafood concerns at all. Pairing your sushi meal with a side salad or miso soup helps balance out the carbohydrate-heavy nature of rice-based dishes.