During pregnancy, your immune system shifts in ways that make you more vulnerable to certain foodborne infections, and some substances can cross the placenta and directly affect your baby’s development. The foods to avoid fall into a few clear categories: those carrying bacterial or parasitic risk, those containing mercury or other toxins, and those with compounds that can harm a developing fetus at any dose.
Fish High in Mercury
Mercury accumulates in large, long-lived predatory fish and can damage a developing baby’s brain and nervous system. The FDA and EPA identify seven fish to avoid entirely during pregnancy: king mackerel, marlin, orange roughy, shark, swordfish, Gulf of Mexico tilefish, and bigeye tuna.
Fish itself is not the enemy. It’s one of the best sources of omega-3 fatty acids, which support fetal brain development. The goal is to choose low-mercury options and eat two to three servings per week, with one serving counting as 4 ounces during pregnancy. Salmon, shrimp, sardines, catfish, cod, tilapia, pollock, and canned light tuna (skipjack) are all in the FDA’s lowest-mercury “Best Choices” category. So are shellfish like crab, clams, scallops, and oysters, as long as they’re fully cooked.
Deli Meats, Hot Dogs, and Smoked Seafood
Listeria is the bacteria that makes cold ready-to-eat meats risky during pregnancy. Unlike most foodborne bacteria, Listeria grows at refrigerator temperatures, which means deli-sliced turkey, ham, salami, hot dogs straight from the package, and refrigerated smoked salmon or lox can all harbor it. Pregnant women are significantly more susceptible to listeriosis than the general population, and the consequences are severe: miscarriage, stillbirth, premature delivery, or serious infection in the newborn including meningitis.
You don’t have to give up these foods entirely. Heating deli meats and hot dogs until they’re steaming hot (165°F internally) kills Listeria. The same goes for smoked seafood: it’s safe when cooked into a dish like a casserole. Refrigerated pâtés and meat spreads should also be avoided unless they’re shelf-stable (canned) versions.
Soft Cheeses and Unpasteurized Dairy
Soft cheeses made from raw (unpasteurized) milk are another common source of Listeria. The CDC specifically flags brie, camembert, blue-veined cheeses, and queso fresco-type cheeses including queso blanco and requesón. Even when made with pasteurized milk, fresh soft cheeses like queso fresco still carry enough risk that the CDC lists them as a “riskier choice” regardless of pasteurization status.
Hard cheeses made with pasteurized milk, such as cheddar, Parmesan, Swiss, and Asiago, are safe. So are cottage cheese, cream cheese, string cheese, feta, and mozzarella when made with pasteurized milk. If you want a soft cheese that’s normally on the avoid list, heating it to 165°F (until it’s steaming or bubbly) makes it safe. The same rule applies to cheese sliced at a deli counter. Raw milk itself, whether from cows, goats, or sheep, should be avoided entirely.
Undercooked Meat, Poultry, and Eggs
Raw and undercooked meat carries two major risks during pregnancy: Toxoplasma, a parasite found especially in undercooked pork, lamb, and venison, and various bacteria including Salmonella and E. coli. Toxoplasma infection during pregnancy can cause intellectual disability, seizures, blindness, and damage to the brain, heart, or kidneys in the baby.
Safe internal temperatures to remember:
- Beef, pork, lamb, and veal steaks, roasts, and chops: 145°F, then let rest for 3 minutes before cutting
- Ground meat of any kind: 160°F (no pink center)
- All poultry, whether whole, ground, or in parts: 165°F
A food thermometer is the only reliable way to check. Color alone doesn’t confirm doneness. Raw or runny eggs carry Salmonella risk, so homemade Caesar dressing, raw cookie dough, hollandaise, and any dish with undercooked eggs should be skipped unless made with pasteurized eggs.
Raw Sprouts and Unwashed Produce
Raw sprouts (alfalfa, clover, mung bean, radish) are grown in warm, humid conditions that are ideal for bacteria. They’ve been linked to repeated Salmonella and E. coli outbreaks and are best avoided entirely during pregnancy, since washing doesn’t reliably remove bacteria that have grown into the sprout itself.
Other raw fruits and vegetables are fine as long as you wash them thoroughly, including the outer rind of melons and the skin of produce you plan to peel. Soil on unwashed vegetables can carry Toxoplasma, so scrub root vegetables well and wash your hands after handling soil, sand, or unwashed produce.
Alcohol
No amount of alcohol is considered safe during pregnancy. The CDC, the American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, and the American Academy of Family Physicians all recommend complete abstinence. Alcohol crosses the placenta freely, and exposure can cause a range of permanent problems collectively known as fetal alcohol spectrum disorders, including physical abnormalities, learning disabilities, and behavioral issues. There is no trimester during which drinking is risk-free, and no type of alcohol (beer, wine, spirits) is safer than another.
Caffeine
You don’t need to eliminate caffeine, but you should keep it under 200 mg per day. That’s roughly one 12-ounce cup of brewed coffee. The American College of Obstetricians and Gynecologists found that moderate intake below this threshold does not appear to be a major contributing factor to miscarriage or preterm birth.
Keep in mind that caffeine adds up from multiple sources: tea (25 to 50 mg per cup), cola (about 35 mg per can), dark chocolate (around 20 mg per ounce), and some energy drinks (which can exceed 200 mg in a single serving and should generally be avoided). If you’re a heavy coffee drinker, tapering gradually helps avoid withdrawal headaches.
Herbal Teas and Supplements
Herbal products aren’t regulated the same way as food or medicine, and many lack human safety data during pregnancy. A study in Frontiers in Pharmacology found that 40% of commonly used medicinal herbs were either contraindicated or recommended for use with caution during pregnancy. Chamomile tea in moderate amounts is generally considered safe, but excessive consumption has been flagged as a potential uterine stimulant.
The safest approach is to stick with common culinary herbs in normal cooking amounts and treat concentrated herbal teas, tinctures, and supplements with skepticism unless your provider has specifically reviewed the ingredient list. “Natural” does not mean safe for pregnancy.
Liver and Vitamin A
Organ meats, particularly liver, contain extremely high concentrations of preformed vitamin A (retinol). In large amounts, retinol is teratogenic, meaning it can cause birth defects. While documented cases in humans are relatively rare (fewer than 20 reported over 30 years of research), the risk is real enough that most guidelines recommend limiting liver consumption during pregnancy rather than eating it regularly. A small serving occasionally is unlikely to be harmful, but making liver pâté or liver and onions a weekly habit pushes intake into potentially dangerous territory. This same concern applies to high-dose vitamin A supplements, so check that your prenatal vitamin contains beta-carotene (the plant-based form your body converts as needed) rather than preformed retinol.
Quick-Reference List
- Avoid entirely: alcohol, high-mercury fish (shark, swordfish, king mackerel, marlin, orange roughy, bigeye tuna, Gulf tilefish), raw sprouts, unpasteurized milk
- Avoid unless heated to steaming (165°F): deli meats, hot dogs, soft cheeses, smoked seafood
- Avoid unless fully cooked to safe temps: all meat, poultry, seafood, and eggs
- Limit: caffeine (under 200 mg/day), liver and organ meats, herbal teas