Ceviche is a popular dish consisting of seafood marinated in an acidic citrus mixture, which gives the fish an opaque and firm texture. The question of whether this traditional dish is safe during pregnancy is common, especially since the dish appears cooked. However, due to the inherent risks associated with raw or undercooked seafood, traditional ceviche is generally not recommended for pregnant individuals. This caution prioritizes the health of both the mother and the developing fetus.
Understanding Acid Curing
The preparation of ceviche relies on acid curing or denaturation, which is often mistaken for cooking with heat. When raw fish or shellfish is steeped in citrus juice, the acid causes proteins to break down and restructure. This changes the seafood’s appearance from translucent to opaque white and gives it a firmer texture, similar to applying heat.
Despite this visual change, acid denaturation is fundamentally different from thermal cooking. Heat sterilization requires the food to reach a specific internal temperature, typically 145°F (63°C) for finfish, to destroy harmful bacteria and parasites effectively. The mild acidity of a citrus marinade cannot achieve the same level of microbial elimination as sustained heat.
The penetration of the acid is often limited, meaning pathogens or parasites deep within the fish muscle may remain largely unaffected. While the acidic environment may inhibit the growth of some surface bacteria, it is not a reliable method for complete sterilization. This distinction is why health guidelines advise caution regarding ceviche consumption during pregnancy.
The Risks of Pathogens and Parasites
The risk of consuming traditional ceviche during pregnancy stems from pathogens and parasites that survive the acid marinade. Pregnant individuals have a suppressed immune system, making them more susceptible to foodborne illnesses and increasing the severity of infections for both mother and baby.
The bacterium Listeria monocytogenes is a major concern due to its high survival rate in acidic environments. Listeriosis, the resulting illness, is dangerous during pregnancy, increasing the risk of miscarriage, stillbirth, and severe neonatal infections. Maternal symptoms can be mild or absent, allowing the infection to be unknowingly passed to the fetus.
Raw seafood also carries the risk of parasitic contamination, such as roundworms from the Anisakis family, which cause anisakiasis. These parasites often reside deep within the fish muscle and are not reliably killed without proper heat or freezing treatment. Salmonella and Vibrio bacteria are other potential contaminants that can lead to severe gastrointestinal illness and dehydration.
Ensuring Safe Seafood Consumption
For pregnant individuals who wish to enjoy seafood, the focus must shift entirely to fully cooked preparations. All seafood consumed during pregnancy should be cooked to an internal temperature of 145°F (63°C) to eliminate harmful microorganisms. The fish should appear opaque and flake easily with a fork to confirm it is done.
A safe alternative to traditional ceviche is to modify the recipe by fully cooking the fish or shellfish first. Cooked shrimp, scallops, or firm white fish can then be marinated in the citrus and other ingredients to achieve the characteristic flavor profile. This method preserves the taste while removing the biological risk associated with raw seafood.
Expectant mothers are encouraged to consume 8 to 12 ounces of low-mercury fish per week for beneficial omega-3 fatty acids. Avoiding high-mercury options like shark, swordfish, and king mackerel remains important for fetal neurological development. Low-mercury options include:
- Salmon
- Cod
- Tilapia
- Canned light tuna