Food Safety in Pregnancy
Listeria, Raw Foods, and What to Skip
Evidence grade 4 of 5, Strong. Read how the Atlas grades evidence.
0 human trials, about 0 studies, Public-health guidance + surveillance data. The written rationale for this grade is still being prepared.
- FDA
- CDC/FDA/ACOG food-safety guidance for pregnancy
- WADA
- Not prohibited
Reference only. Not medical advice.
What can go wrong
The risk here is the foods themselves acting as infection vectors. Listeria is the standout because it grows at refrigerator temperatures and can cause miscarriage, stillbirth, or severe newborn infection from mild or silent maternal illness; Toxoplasma (undercooked meat, unwashed produce, cat litter and soil) can likewise infect the fetus quietly, and Salmonella (raw eggs, undercooked poultry) and Vibrio (raw shellfish) add further reasons to cook and choose carefully. The core guidance is consistent across CDC, FDA, and ACOG: choose pasteurized dairy and juice, heat deli meats and hot dogs to steaming hot or 165F, cook eggs until firm, cook meat and poultry to safe internal temperatures with a thermometer, wash produce, and skip raw fish, raw sprouts, and refrigerated smoked seafood unless cooked into a dish. This entry is educational and not a substitute for prenatal care. Anyone who develops fever or flu-like symptoms in pregnancy, or who is worried about a specific exposure, should contact their obstetric provider promptly rather than wait, since early evaluation and, where indicated, antibiotics matter.
Pregnancy changes what is safe to eat because the immune adaptations that let a pregnancy continue also raise susceptibility to a few foodborne infections, most sharply listeriosis. CDC surveillance puts the risk of Listeria infection in pregnancy at roughly ten times that of the general population, and the bacterium can cross the placenta to cause miscarriage, stillbirth, or severe newborn infection even when the mother feels only mildly ill or not ill at all. Toxoplasma behaves the same way, infecting the fetus quietly. The practical response is a focused avoid-list, not blanket anxiety: unpasteurized milk and soft cheeses, unheated deli meats and hot dogs, refrigerated pate and cold-smoked seafood, raw or undercooked fish, eggs, meat, and poultry, unwashed produce, and raw sprouts. This is a contamination question rather than a nutrient one, and it belongs in any complete prenatal picture.
Not a nutrient question but a contamination one: pregnancy raises the risk from certain foodborne pathogens, especially Listeria, enough to change what is safe to eat.
What people take it for
What it is taken for. Approval, where it exists, covers only some of these.
What people get wrong
Often saidFood safety in pregnancy is just general healthy-eating advice.
ActuallyIt is specifically about infection risk, not nutrition. CDC surveillance shows pregnancy raises Listeria susceptibility roughly tenfold, and Listeria can cause severe fetal harm from foods that would barely register in a non-pregnant adult.
Often saidIf the mother feels fine, the food was safe for the baby.
ActuallyNot reliably. Both Listeria and Toxoplasma can cross the placenta and harm the fetus while the mother has only mild flu-like symptoms or none, which is exactly why the avoid-list is precautionary rather than symptom-triggered.
Often saidOnly unpasteurized cheeses carry Listeria; sealed or pre-packaged foods are safe.
ActuallyListeria grows at refrigerator temperatures and has been traced to deli meats, hot dogs, refrigerated smoked seafood, pre-cut celery, and cantaloupe. CDC advises heating deli meats and hot dogs to steaming hot or 165F rather than assuming a sealed package is safe.
Often saidToxoplasma risk is only about cat litter.
ActuallyUndercooked meat and unwashed produce are major routes too. FDA estimates roughly half of U.S. toxoplasmosis infections are foodborne, which is why cooking meat to safe temperatures and washing produce matter alongside litter-box precautions.
Who profits, and who pushes back
CDC
Pregnant people are about ten times more likely to get listeriosis, which can cause miscarriage, stillbirth, premature delivery, or life-threatening newborn infection; high-risk foods should be avoided or heated.
ACOG
Pregnant women should avoid all raw and undercooked seafood, eggs, and meat, and unpasteurized dairy, due to infection risks including Listeria.
FDA / food-safety authorities
Heating deli meats and hot dogs until steaming, choosing pasteurized products, and washing produce reduce listeriosis and other foodborne risks in pregnancy.
Proportion caveat
The aim is sensible precaution, not fear; the avoid-list is targeted, and most foods remain safe when handled and cooked properly.
Where the research comes from
Most of the published research on this comes from one place. 100% of it is from Higher listeriosis risk in pregnancy. Findings that no unrelated group has reproduced are weaker than the study count makes them look.
| Place | Share of published research |
|---|---|
| Higher listeriosis risk in pregnancy | 100% |
Research published from: Global.
How we got here
Listeria monocytogenes was first described in 1926 by E.G.D. Murray and colleagues at Cambridge, working from sudden deaths in laboratory rabbits and guinea pigs; the South African physician J.H.H. Pirie, studying the same organism in wild gerbils near Johannesburg, gave the genus the name Listeria in 1940 in reference to Joseph Lister. For decades the bacterium was viewed as an animal and sporadic-human problem rather than a food one. That changed in 1981, when William Schlech and colleagues traced a Nova Scotia outbreak of 34 perinatal and 7 adult cases to coleslaw made from cabbage grown in fields fertilized with manure from listeriosis-affected sheep. Published in the New England Journal of Medicine, it was the first firmly documented foodborne listeriosis outbreak and reframed the infection as a food-safety concern with a distinctive tilt toward pregnant people and newborns. Modern CDC, FDA, and ACOG pregnancy guidance grew from that surveillance base and the outbreaks that followed.
- 1926Murray and colleagues at Cambridge describe the bacterium later named Listeria, from deaths in lab rabbits and guinea pigs
- 1940J.H.H. Pirie names the genus Listeria, honoring Joseph Lister
- 1981Schlech et al. link a Nova Scotia outbreak (34 perinatal, 7 adult cases) to contaminated coleslaw; first documented foodborne listeriosis, published in NEJM
- 1985A Los Angeles outbreak tied to Mexican-style soft cheese kills dozens, many of them pregnant women and newborns, cementing the pregnancy focus
- 2009-2011CDC Vital Signs surveillance quantifies pregnancy relative risk at about 10 (RR 10.1), with 14 percent of cases pregnancy-associated; soft cheese the leading vehicle
- 2024A multistate Listeria outbreak traced to deli meats sliced at delis sickens 61 people across 19 states with 10 deaths, prompting a large Boar's Head recall
At a glance
- Listeria risk
- ~10x higher in pregnancy
- Avoid
- Unpasteurized dairy, deli meats, raw fish/eggs
- Cook to
- Safe internal temperatures
- Why
- Fetal infection can be severe
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Food Safety in Pregnancy. A short entry is not a safe entry.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
Sources
Pregnant women are 10 times more likely to get a Listeria infection; avoid-list and cook-to temperatures
Listeriosis relative risk in pregnancy RR 10.1; 14% of cases pregnancy-associated; soft cheese leading vehicle
CDC Vital Signs: Listeria Illnesses, Deaths, and Outbreaks, United States 2009-2011 (via PMC)
Listeriosis during pregnancy is typically mild for the mother but ~25% of pregnancy-associated cases end in fetal loss or newborn death
About 1 in 25,000 pregnancies affected annually; 1 in 4 who get listeriosis lose the pregnancy or newborn; pregnant people are a Listeria risk group
ACOG cites listeriosis incidence ~13x general population; avoid-list and exposure-management algorithm
First documented foodborne listeriosis outbreak (Nova Scotia, 1981) traced to coleslaw; 34 perinatal and 7 adult cases; evidence for transmission by food
Listeria first described 1926 by Murray et al. at Cambridge; genus named Listeria by Pirie in 1940
Toxoplasma prevention: cook meat to safe internal temperatures, freeze meat, wash produce, daily litter-box changes, gloves for gardening; parasite non-infectious until 1-5 days after shedding
Toxoplasma transmission routes (undercooked meat, unwashed produce, cat feces) and congenital risk; can infect fetus silently
Combined US pregnancy food-safety avoid-list and safe cooking temperatures (eggs 160F, poultry 165F); pregnancy raises foodborne illness risk
FoodSafety.gov (HHS/USDA/FDA), People at Risk: Pregnant Women
2024 multistate Listeria outbreak from deli meats: 61 illnesses, 19 states, 60 hospitalizations, 10 deaths; Boar's Head recall