No single food reliably “causes” a miscarriage in an otherwise healthy pregnancy. Most miscarriages happen because of chromosomal abnormalities that no diet change can prevent. But certain foods do carry infections or toxic compounds that significantly raise the risk of pregnancy loss, stillbirth, or serious birth defects. Knowing which foods pose real danger, and why, lets you make informed choices about what to eat and how to prepare it.
Why Some Foods Are Dangerous During Pregnancy
Your immune system dials down during pregnancy so your body doesn’t reject the developing fetus. That trade-off makes you far more vulnerable to foodborne pathogens. Pregnant women are 10 times more likely to develop a Listeria infection than the general population, according to the CDC. Infections from Listeria, Salmonella, Toxoplasma, and E. coli can cross the placenta or trigger intense inflammatory responses that lead to miscarriage, preterm labor, or stillbirth.
The foods below aren’t dangerous because of some mysterious property. They’re dangerous because they’re common vehicles for these specific pathogens, or because they contain compounds that are toxic to a developing embryo at certain doses.
Deli Meats, Hot Dogs, and Cold Cuts
Listeria thrives in refrigerated, ready-to-eat foods, and deli meats are one of its most common hiding places. Unlike most bacteria, Listeria grows at refrigerator temperatures, so even properly stored cold cuts can harbor it. A Listeria infection during pregnancy can cause miscarriage, stillbirth, or life-threatening illness in a newborn.
The risk isn’t limited to cheap cold cuts. Refrigerated pâtés, meat spreads, fermented sausages, and premade deli salads (chicken salad, tuna salad, egg salad, coleslaw) all fall into this category. If you want to eat deli meat, heat it to an internal temperature of 165°F or until it’s steaming hot. That kills Listeria reliably.
Soft and Fresh Cheeses
Soft cheeses made from unpasteurized (raw) milk are a well-documented source of Listeria. Brie, camembert, blue-veined cheese, and queso fresco-type cheeses like queso blanco and requesón are the main ones to watch. The FDA warns that queso fresco-type cheeses carry risk even when made from pasteurized milk, because their high moisture and low acidity still allow Listeria to grow.
Hard cheeses and cheese that’s been cooked into a dish are generally fine. If you’re buying soft cheese, check the label for the word “pasteurized” and be cautious with anything sliced fresh at a deli counter, which can pick up contamination from shared equipment.
Raw and Undercooked Meat
Undercooked beef, pork, and lamb are the primary dietary sources of Toxoplasma gondii, a parasite that can cross the placenta and cause miscarriage or severe birth defects. Raw or rare poultry carries Salmonella risk on top of that. Safe internal temperatures vary by meat type:
- Whole cuts of beef, pork, or lamb: 145°F, then let the meat rest for three minutes before cutting
- Ground meat (beef, pork, lamb): 160°F, no rest time needed
- All poultry, whole or ground: 165°F, checked at the thickest part
A food thermometer is the only reliable way to confirm these temperatures. Color alone doesn’t tell you enough.
Raw and Undercooked Eggs
Runny eggs, homemade Caesar dressing, raw cookie dough, homemade eggnog, and any batter made with raw eggs can carry Salmonella. A severe Salmonella infection causes dehydration, high fever, and cramping that can trigger preterm contractions. Cook eggs until both the yolk and white are firm. Commercially pasteurized egg products are a safe substitute in recipes that call for raw eggs.
High-Mercury Fish
Mercury doesn’t cause miscarriage directly, but it accumulates in fetal brain and nervous system tissue, causing developmental damage. The FDA lists seven fish to avoid entirely during pregnancy because of their high mercury levels: shark, swordfish, king mackerel, marlin, orange roughy, bigeye tuna, and Gulf of Mexico tilefish.
Fish itself isn’t the enemy. The FDA recommends pregnant women eat 8 to 12 ounces per week of low-mercury seafood (salmon, shrimp, tilapia, pollock, catfish, and others on the “Best Choices” list). That’s two to three 4-ounce servings. The omega-3 fatty acids in fish actively support fetal brain development, so cutting out seafood entirely can work against you.
Raw Seafood and Smoked Fish
Sushi, sashimi, ceviche, and raw oysters can carry Listeria, parasites, and Vibrio bacteria. Refrigerated smoked seafood, typically labeled as “lox,” “nova-style,” “kippered,” or “smoked,” also poses a Listeria risk unless it’s been cooked into a dish like a casserole. Canned or shelf-stable smoked fish is fine because the canning process kills bacteria.
Raw Sprouts and Unwashed Produce
Raw sprouts, including alfalfa, clover, mung bean, and radish, are uniquely risky because bacteria like E. coli and Salmonella can get inside the seed itself before it sprouts. Washing doesn’t remove them. The only way to make sprouts safe is to cook them thoroughly.
Unwashed fruits and vegetables can carry Toxoplasma from contaminated soil, along with Listeria and other pathogens. Rinse all produce under running water, even if you plan to peel it. Pre-cut melon left at room temperature for more than two hours (one hour if it’s above 90°F) also becomes a bacterial risk and should be discarded.
Unpasteurized Milk and Juice
Raw milk and unpasteurized juices or ciders can harbor Listeria, Salmonella, and E. coli. Pasteurization exists specifically to kill these organisms without changing the nutritional value in any meaningful way. This applies to any dairy product made from raw milk, including yogurt, ice cream, and butter from small farms or farmers’ markets that don’t pasteurize.
Excessive Vitamin A From Animal Sources
Preformed vitamin A (the type found in liver, liver pâté, and high-dose supplements) is teratogenic in large amounts, meaning it causes birth defects. The risk is highest in the first 60 days after conception. The World Health Organization sets the safe upper limit at 10,000 IU per day during pregnancy. A single 3-ounce serving of beef liver can contain over 25,000 IU, so it’s worth limiting or avoiding liver during early pregnancy. The plant-based form of vitamin A found in carrots, sweet potatoes, and leafy greens (beta-carotene) does not carry this risk because your body only converts what it needs.
Caffeine
Caffeine in moderate amounts does not appear to be a major contributor to miscarriage. The American College of Obstetricians and Gynecologists puts the threshold at less than 200 mg per day, roughly one 12-ounce cup of brewed coffee. Neither of the two large studies ACOG reviewed showed a significant increase in miscarriage risk below that level. Above 200 mg, the evidence is conflicting, so a firm recommendation either way isn’t possible. If you drink coffee, tea, or energy drinks, it’s worth tracking your total daily intake rather than guessing.
Raw Dough and Batter
This one surprises people. Raw flour, not just raw eggs, is a contamination risk. Flour is a raw agricultural product that can carry E. coli from the field, and it isn’t treated with a kill step before packaging. Tasting raw cookie dough or cake batter exposes you to both the flour risk and the raw egg risk. Bake or cook any flour-based product before eating it.
What This Means in Practice
The common thread across nearly every item on this list is preparation, not the food itself. Meat, eggs, fish, cheese, and produce are all nutritious parts of a pregnancy diet when they’re properly cooked, pasteurized, or thoroughly washed. The handful of true “avoid entirely” items is short: high-mercury fish, raw sprouts, unpasteurized dairy, liver in large amounts, and any food you can’t verify has been handled safely.
A food thermometer, a habit of checking labels for the word “pasteurized,” and basic produce washing go further than any list of forbidden foods. Most pregnancy losses are caused by factors completely outside dietary control, but foodborne illness is one risk you can meaningfully reduce.