Pregnancy is a time of excitement and change, but also of caution as it involves the growth and development of one or more fetuses. While healthy eating is crucial during pregnancy, there are certain foods pregnant women should avoid due to potential health risks for themselves and their developing babies.
One such food is raw fish, which has been linked to an increased risk of infections caused by harmful bacteria, viruses, and parasites. The New York Times (NYT) reported on this topic in detail, highlighting why experts advise against consuming raw fish during pregnancy.
“Raw fish dishes like sushi and sashimi have become an international delicacy, but they may not be completely safe for everyone,” warns Dr. Jennifer Wu, obstetrician-gynecologist at Lenox Hill Hospital in New York City. “Pregnant women are particularly vulnerable as their immune system is compromised.”
In this article, we will explore the reasons behind this advice and what alternatives pregnant women can choose instead of raw fish. We will also discuss essential nutrients that should make up a healthy pregnancy diet, so you can make informed decisions about your nutrition during gestation.
Mercury Exposure Risks
Mercury is a naturally occurring metal that can be found in the air, water, and soil. While low levels of mercury exposure are generally considered safe, high levels have been linked to health problems.
Health Risks Associated with Mercury Consumption
Pregnant women are advised against eating raw fish because of the risk of mercury exposure. High levels of mercury consumption during pregnancy have been linked to developmental delays, brain damage, and even miscarriage.
Children and infants are also at increased risk from mercury exposure. Developmental delays, neurological disorders, and learning disabilities are all possible outcomes from high levels of mercury exposure in early childhood.
In adults, high levels of mercury exposure can lead to tremors, memory loss, kidney damage, and even death in extreme cases.
“Even small amounts of mercury can cause serious health problems over time,” warns Dr. Leonardo Trasande, an environmental medicine specialist at New York University.
Precautionary Measures to Limit Mercury Exposure
There are steps you can take to reduce your risk of mercury exposure. One of the most important is to limit your consumption of certain types of fish, especially those higher up on the food chain. Large predatory fish like shark, swordfish, king mackerel, and tilefish are known to contain high levels of mercury.
You can still enjoy seafood while minimizing your risk of mercury exposure by choosing safer options such as shrimp, salmon, tilapia, and catfish. These fish tend to be lower in mercury and other harmful contaminants.
It’s not just pregnant women who should be mindful of their seafood intake. Anyone can benefit from being aware of which fish are more likely to contain high levels of mercury. The Environmental Protection Agency and the Food and Drug Administration both have guidelines for safe seafood consumption that are easy to follow.
“It’s important to balance the nutritional benefits of fish with the potential risks, especially for pregnant women and young children,” says Dr. Laura Riley, a high-risk pregnancy specialist at Weill Cornell Medicine in New York City.
In addition to being careful about what you eat, it’s also wise to avoid any products that contain mercury or its derivatives whenever possible. This includes certain types of batteries, light bulbs, thermometers, and even some skin-lightening creams.
By following these simple precautions, you can significantly reduce your risk of mercury exposure and enjoy all the health benefits associated with eating seafood.
Raw fish and seafood products may contain harmful bacteria that can pose serious health risks to vulnerable populations such as pregnant women. The following bacterial infections are commonly associated with the consumption of raw or undercooked seafood:
Vibrio Infections from Raw Seafood Consumption
Vibrio, a type of bacteria found in saltwater, is a common cause of foodborne illness associated with raw oysters, clams, and other shellfish. Symptoms of Vibrio infection (vibriosis) include diarrhea, vomiting, abdominal pain, and fever. In severe cases, Vibrio infection can lead to bloodstream infections and septicemia.
Pregnant women are at heightened risk of contracting vibriosis because pregnancy suppresses the immune system, making it more difficult for the body to fight off infection. Additionally, Vibrio bacteria have a higher chance of causing severe disease in pregnant women due to changes in the maternal physiology.
“Pregnancy supresses the maternal immune system necessary for fetal survival but leaves expectant mothers susceptible to bacterial and viral infections.” – University of Rochester Medical Center
Salmonella Infections from Contaminated Seafood
Salmonella is a type of bacteria that causes an estimated 1.35 million infections in the United States each year, many of which are caused by contaminated seafood. Symptoms of salmonella infection include fever, diarrhea, and stomach cramps that typically develop within 12 to 72 hours after eating the contaminated food.
Pregnant women are particularly vulnerable to salmonellosis since the infection can spread to the fetus, causing premature birth, fetal death, or stillbirth.
“The dangers of salmonella during pregnancy go beyond their own health—unborn babies can be infected, resulting in everything from a mild fever to the possibly fatal infection of the entire body.” – Parents.com
Campylobacter Infections from Undercooked Seafood
Like salmonella, Campylobacter is another harmful bacterium that can contaminate raw or undercooked seafood. Symptoms of Campylobacter infection include diarrhea (often bloody), fever, abdominal pain, and vomiting. The illness usually lasts for one week.
Pregnant women are at higher risk of contracting campylobacteriosis since pregnancy alters the digestive system’s structure and function. Additionally, if left untreated during pregnancy, Campylobacter infections have been associated with preterm labor and other severe fetal complications.
“Campylobacter is just one more bacteria that can lead to maternal issues and even premature birth when contracted during pregnancy.” – What To Expect
- To prevent bacterial infections associated with raw or undercooked seafood consumption, pregnant women should avoid all uncooked fish and shellfish products, including sushi, sashimi, ceviche, crudo, poke bowls, and oyster shooters.
- If cooked, seafood should be thoroughly cooked until it reaches an internal temperature of 145°F (63°C) as measured by a food thermometer.
- Pregnant women should also wash their hands and kitchen surfaces before handling and preparing seafood products.
Consuming raw or undercooked seafood poses significant health risks for pregnant women, particularly concerning Vibrio, Salmonella, and Campylobacter infections. Pregnant women should abstain from eating any uncooked seafood product to reduce these risks and protect themselves and their unborn baby from potential harm.
Tapeworm Infections from Raw or Undercooked Fish
One of the primary reasons pregnant women are advised against eating raw fish is because it can lead to tapeworm infection. Tapeworms are flat, segmented worms that can grow up to 30 feet long and live in the human gut. The most common way for humans to acquire this parasite is by consuming raw or undercooked freshwater fish such as salmon, trout, and perch.
The CDC warns that tapeworm infections can be particularly harmful to pregnant women and their babies because the worm’s larvae can move away from the intestines and infect organs such as the eyes, heart, and brain. If a tapeworm larva migrates to a baby’s brain, it can cause seizures, developmental delays, and even death. Symptoms of tapeworm infection include abdominal pain, diarrhea, weight loss, and fatigue.
Anisakiasis from Consuming Infected Fish
Another parasitic infection that can result from eating raw or inadequately cooked fish is anisakiasis. This condition occurs when someone eats contaminated fish containing Anisakis larvae. When ingested, these parasites burrow into the lining of the stomach or intestine and can cause severe abdominal pain, vomiting, and diarrhea. According to Dr. Robert Tauxe, director of foodborne, waterborne, and environmental diseases at the Centers for Disease Control and Prevention, “Consumers should be aware that there is always some level of risk involved in eating raw or undercooked fish.”
Giardia Infections from Eating Raw Shellfish
While many people associate parasitic infections with fish consumption, raw shellfish can also harbor dangerous bacteria and parasites. One such infection is caused by Giardia, a microscopic parasite that can cause diarrhea and other gastrointestinal symptoms. Pregnant women who consume raw shellfish are at increased risk of developing this infection because the parasite can pass through the placenta to harm their developing fetus.
According to Dr. Anne Schuchat, director of the CDC’s National Center for Immunization and Respiratory Diseases, “The safest thing to do is not eat any raw or undercooked seafood during pregnancy.”
Amoebic Dysentery from Contaminated Shellfish
An additional parasitic infection that can result from consuming contaminated shellfish is amoebic dysentery. This condition is caused by Entamoeba histolytica, a single-celled amoeba found in infected feces. If an individual ingests food or water contaminated with these parasites, they can develop severe abdominal pain, bloody diarrhea, and dehydration.
Pregnancy is known to weaken the immune system which makes expecting mothers susceptible to catching infections more easily than other people. So if you’re pregnant, it is important to avoid eating high-risk foods like raw fish and oysters completely to be on the safe side.
Possible Allergic Reactions
Seafood is a common allergen, and pregnant women are advised against consuming raw fish due to the risk of foodborne illness and possible allergic reactions. The following sections discuss potential allergic reactions, cross-reactivity to other allergens, severity of symptoms, and preventative measures for those who have allergies.
Allergic Reactions to Seafood Proteins
The proteins found in seafood can cause an allergic reaction in some people. According to the American College of Allergy, Asthma & Immunology, seafood allergy affects approximately 1-2% of adults. Symptoms of a seafood allergy may include hives, itchiness, swelling of the lips, tongue, or throat, difficulty breathing, nausea, vomiting, diarrhea, and in severe cases, anaphylaxis.
Anaphylaxis is a life-threatening allergic reaction that requires immediate medical attention. It can lead to shock, low blood pressure, respiratory failure, and cardiac arrest. Pregnant women who experience any symptoms of a seafood allergy should seek medical help right away.
Cross-Reactivity to Other Allergens
A person with a seafood allergy may also be allergic to certain types of protein found in other foods such as eggs, milk, wheat, soy, peanuts, and tree nuts. This is known as cross-reactivity. Although the actual rate of cross-reactivity between seafood and these other allergens is unknown, it is recommended that individuals with a seafood allergy avoid these foods until they consult their doctor or allergist.
Severity of Allergic Reactions
The severity of an allergic reaction can vary from person to person. In rare cases, a person may develop a severe form of seafood allergy known as shellfish poisoning. According to the U.S. Food and Drug Administration (FDA), this condition is caused by a toxin produced in some types of shellfish, such as mussels, clams, and oysters. Symptoms include tingling or burning sensation in the mouth, throat, or limbs; dizziness; headache; nausea; vomiting; paralysis; respiratory failure, and in extreme cases, death.
While pregnant women are at an increased risk of developing severe symptoms due to changes in their immune system, there is no evidence that they are more susceptible to seafood allergy than non-pregnant individuals. However, it is important to note that any allergic reaction during pregnancy can affect both the mother and fetus.
Preventative Measures for Allergic Individuals
If you have a seafood allergy, the most effective way to prevent an allergic reaction is to avoid all types of seafood. This includes fish, crustaceans like shrimp, lobster, and crab, and mollusks, such as clams, oysters, and scallops. Avoiding food items prepared using fish oils, sauces, or seasonings made with seafood is also recommended.
In addition to avoiding seafood, individuals with allergies should always carry prescribed medications such as auto-injectable epinephrine, antihistamines, and asthma inhalers. They must inform their friends, family, and caregivers about their allergy, how to recognize an allergic episode, and what steps to take in case of emergency.
“It’s crucial to identify a seafood allergy early, so the person can avoid foods that trigger a reaction,” says Dr. James T C Li, chair of the division of Allergic Diseases at Mayo Clinic. “It’s essential to start appropriate treatment promptly if someone has an allergic reaction after consuming seafood.”
Allergic reactions to seafood can occur suddenly and without warning, so anyone who experiences symptoms after eating seafood should seek medical attention right away. By taking the necessary precautions, pregnant women and others with allergies can enjoy a safe and healthy pregnancy.
Impact on Fetal Development
Pregnancy is a critical period, and expecting mothers have to be careful about everything they eat. Raw fish is a delicacy in many cultures but pregnant women are advised against eating it due to the potential impact on fetal development.
Increased Risk of Mercury Exposure for Pregnant Women
Mercury exposure is a severe concern among pregnant women who consume seafood regularly, including raw fish. The mercury content in some types of high-end sushi can accumulate over time and pose serious health risks. Ingesting high levels of mercury during pregnancy can impair fetal brain and nervous system development, affecting learning abilities, memory retention, and overall cognitive functions.
“The developing fetus is especially sensitive to the toxic effects of methylmercury, and the majority of prenatal exposures result from maternal consumption of contaminated fish” -Center for Disease Control and Prevention (CDC)
Although the amount of mercury an individual consumes depends on the type of fish and their intake frequency, experts advise pregnant women to avoid big and predatory fish altogether to minimize risk.
Effects of Mercury on Fetal Brain Development
Studies show that prenatal mercury exposure results in developmental disorders, and long-term neurological damage in newborns and young children. Exposure to high amounts of mercury at the embryonic or fetal stage increases susceptibility to neurodegenerative diseases like Alzheimer’s dementia later in life. Methylmercury-binding compounds found in raw fish easily cross the placenta barrier, thereby exposing developing fetuses to higher chances of toxin accumulation than adults consuming equivalent amounts.
“High levels of mercury include confusion, vision changes, muscle weakness, and poor coordination” -Jean Keller M.D., an OB-GYN practicing in Newport Beach
Expecting mothers should avoid mackerel, shark, swordfish and tuna altogether to reduce the risk of mercury-related developmental delays in their babies. Instead, they should opt for low-mercury fish such as salmon, shrimp, and canned light tuna.
Other Seafood-Related Risks during Pregnancy
In addition to the risks associated with high mercury levels in fish, eating raw fish while pregnant also exposes expectant mothers to other seafood-related risks like bacterial infections. Raw fish carries bacteria and other parasites that could cause food poisoning symptoms like vomiting, abdominal cramps, diarrhea, and dehydration, potentially affecting fetal development.
“One major concern with sushi is that every where it comes from may not be FDA-approved,” -Rajiv Gala, M.D., an OB-GYN based in San Francisco.
Pregnancy changes how a woman’s body handles some infections, including those caused by listeria bacteria present in uncooked fish. Listeriosis can cause complications such as premature labor or stillbirth, which can be fatal to both the mother and the baby.
- Indeed, women are advised to practice proper food hygiene at all times when consuming any delicacies, especially during pregnancy
- During your pregnancy, make sure you practice optimal hand washing techniques with warm water and soap before handling food items, avoid cross-contamination between foods, and discard leftover meals within four days.
- If you must eat sushi, ensure that it undergoes rigorous quality control processes, only consume it from reputable and reliable restaurants that uphold strict safety standards, and choose vegetarian options instead of raw meat dishes
The bottom line is that expecting mothers should take extra precautions during pregnancy, including avoiding certain types of seafood like raw fish to reduce various health risks on their unborn babies’ development. Always speak with your obstetrician before making any significant dietary changes during pregnancy.
Alternative Safe Seafood Options
If you are a seafood lover, but worry about the potential health risks of consuming raw fish during pregnancy, there are several safe and tasty alternatives available. In order to minimize your exposure to harmful pathogens or contaminants that can affect the fetal development and lead to adverse outcomes, it is essential to make informed choices when it comes to selecting your seafood.
Low-Mercury Seafood Options
According to the United States Environmental Protection Agency (EPA) and Food and Drug Administration (FDA), pregnant women should avoid certain types of fish that contain high levels of mercury, such as shark, swordfish, king mackerel, and tilefish. Instead, they recommend consuming low-mercury options such as salmon, trout, sardines, anchovies, shrimp, crab, clams, and oysters. These species not only pose fewer risks of mercury contamination but also provide essential nutrients like protein, omega-3 fatty acids, iron, and zinc that are crucial for the baby’s growth and brain function.
Plant-Based Omega-3 Sources
If you prefer plant-based protein sources, you don’t have to miss out on the benefits of omega-3 fatty acids, which play a vital role in reducing inflammation, improving heart health, and supporting cognitive development. Some excellent vegan or vegetarian sources of omega-3s include chia seeds, flaxseeds, hemp seeds, walnuts, algae oil, and fortified products such as soy milk or breakfast cereals. It is important to note that while these sources do not contain the same type of omega-3s found in fish, they can still contribute to a healthy diet and meet your recommended daily intake.
Sustainable Seafood Choices
Aside from nutritional considerations, another important aspect to consider when choosing seafood is its environmental impact. Overfishing and unsustainable practices can lead to the depletion of marine resources, disrupt ecosystems, and harm other species that depend on them. By selecting sustainably-sourced seafood options, you can support responsible fishing methods that protect and conserve our oceans while ensuring a steady supply for future generations. Look for certifications like Marine Stewardship Council (MSC) or Aquaculture Stewardship Council (ASC), which indicate that the seafood was harvested or farmed in an environmentally-friendly and socially responsible manner.
Seafood Processing and Preparation Tips for Safety
To lower the risk of foodborne illnesses or infections caused by consuming raw or undercooked seafood, it is crucial to handle, store, and cook your seafood properly. Some recommended tips include:
- Keep your seafood refrigerated or frozen until ready to use;
- Thaw frozen seafood in the refrigerator, not at room temperature;
- Clean and sanitize all surfaces, utensils, and hands that come in contact with raw seafood;
- Cook fish to an internal temperature of at least 145°F (63°C) using a food thermometer;
- Avoid cross-contamination by separating cooked from raw seafood, or using separate cutting boards, plates, and knives;
- Discard any seafood that looks or smells abnormal or has passed its expiration date.
“Eating raw or undercooked seafood during pregnancy increases the likelihood of infection with bacteria, viruses, or parasites that can cause severe consequences such as miscarriage, preterm labor, stillbirth, or birth defects,” says Dr. Nicole Avena, author of What to Eat When You’re Pregnant.
While raw fish may be an enticing option for sushi aficionados, pregnant women should take precautions to avoid potential risks and opt for safer alternatives. Whether you prefer low-mercury seafood options, plant-based sources of omega-3s, or sustainable choices, it is essential to make informed decisions that prioritize your health and the well-being of your baby.
Frequently Asked Questions
What are the risks of consuming raw fish during pregnancy?
Consuming raw fish during pregnancy can increase the risk of foodborne illness, such as listeriosis, salmonellosis, and toxoplasmosis. These infections can cause severe harm to the developing fetus and can lead to miscarriage, stillbirth, or preterm birth. Therefore, it is recommended that pregnant women avoid consuming raw fish altogether.
What types of raw fish should pregnant women avoid?
Pregnant women should avoid consuming raw or undercooked fish, especially those that are high in mercury, such as shark, swordfish, king mackerel, and tilefish. They should also avoid raw shellfish, such as oysters, clams, and mussels, as they can contain harmful bacteria and viruses that can cause foodborne illness.
Can cooked fish be a safe alternative for pregnant women?
Yes, cooked fish can be a safe alternative for pregnant women as long as it is properly cooked to an internal temperature of 145°F. Cooking fish can kill harmful bacteria and parasites, making it safe to consume during pregnancy. However, pregnant women should still avoid high-mercury fish and limit their consumption of fish to 2-3 servings per week.
What is the concern with mercury levels in raw fish for pregnant women?
Mercury is a toxic substance that can accumulate in fish and seafood. Consuming high levels of mercury during pregnancy can harm the developing fetus’s nervous system, leading to developmental delays, cognitive deficits, and other neurological problems. Therefore, pregnant women should avoid high-mercury fish, such as shark, swordfish, king mackerel, and tilefish.
Are there any health benefits to consuming raw fish during pregnancy?
Consuming raw fish during pregnancy is not recommended due to the risk of foodborne illness and exposure to harmful substances such as mercury. However, fish is a rich source of omega-3 fatty acids, which are essential for the baby’s brain development. Pregnant women can still obtain the benefits of omega-3s by consuming cooked fish, such as salmon, sardines, and trout, or by taking omega-3 supplements.
What precautions should pregnant women take when consuming fish in general?
Pregnant women should follow some precautions when consuming fish, such as choosing low-mercury fish, limiting their consumption to 2-3 servings per week, and properly cooking the fish to an internal temperature of 145°F. They should also avoid raw or undercooked fish, raw shellfish, and fish that is high in mercury, such as shark, swordfish, king mackerel, and tilefish.