Which foods should be avoided in pregnancy?

The pregnancy food list looks arbitrary until you see that it is really four short lists with a different reason behind each. Once you know whether an item is on there for listeria, toxoplasma, mercury or vitamin A, the borderline cases become much easier to judge — and it explains why home-made preserves and ferments need a second look.

Safety

Step by step

1. Understand the listeria group.Listeria is rare but can cause miscarriage, stillbirth and serious illness in a newborn, and it grows at fridge temperatures, which is why chilled ready-to-eat foods are on the list. This covers unpasteurised milk and its products, mould-ripened soft cheeses such as brie, camembert and chèvre with a white rind, soft blue cheeses, all pâté including vegetable pâté, and cold-smoked or cold-cured fish and meats.
2. Know what thorough cooking does to that group.Cooking these foods until steaming hot all the way through kills listeria, so baked camembert is fine and a pâté cooked into a hot dish is fine. The risk is in eating them cold and ready to eat.
3. Understand the toxoplasma group.Toxoplasmosis comes from raw and undercooked meat, cured meats that have not been cooked, and unwashed vegetables and salad. Cook meat right through with no pink, wash all fruit, vegetables and salad thoroughly, and either avoid cold-cured meats such as parma ham, salami and chorizo or freeze them for four days first, which kills the parasite.
4. Understand the salmonella group.Raw and lightly cooked eggs are the main item, and in the UK the answer depends on the Lion mark. Eggs with the British Lion stamp, or the equivalent Laid in Britain scheme, can be eaten raw or runny in pregnancy. Eggs without it, including most imported and duck, goose and quail eggs, should be cooked until both white and yolk are solid.
5. Understand the mercury and vitamin A limits.These are limits rather than bans. No more than two portions of oily fish a week; no more than two tuna steaks or four medium tins of tuna a week; avoid shark, swordfish and marlin entirely. Avoid liver and liver products, and any supplement containing vitamin A or fish liver oil, because too much vitamin A can harm the baby.
6. Apply it to raw shellfish and sushi.Raw or lightly cooked shellfish is out; cooked shellfish is fine. Raw fish in sushi is generally acceptable in the UK if it has been commercially frozen first, which is standard practice for sushi-grade fish, but home-prepared raw fish should be avoided.
7. Apply it to home preserving and fermenting.Home-fermented vegetables such as sauerkraut and kimchi are unpasteurised live products and are best avoided or cooked, particularly if you cannot be certain the ferment worked properly. Home-brewed kombucha is unpasteurised and contains a little alcohol, and is advised against. Home cold-smoked or home-cured fish and meat should not be eaten at all. Home-made jam, chutney and pickles are fine.
8. Know that alcohol has no safe level.The UK Chief Medical Officers' advice is that the safest approach is not to drink alcohol at all in pregnancy. Caffeine is limited to 200mg a day, which is roughly two mugs of instant coffee or one of filter — remember tea, cola, energy drinks and chocolate all count.
9. Be strict about food safety generally.Pregnancy alters immune function, so the ordinary rules matter more: keep the fridge at 5°C or below, observe use-by dates, reheat leftovers until steaming, avoid food left out too long, and wash hands after handling raw meat and soil-covered vegetables.
10. Check the current NHS list rather than a remembered one.The advice changes — the position on eggs changed substantially in 2017, for example. nhs.uk has the current version, and a midwife can answer the specific cases.

Tips

• Hard cheeses, halloumi, feta, mozzarella, cream cheese, cottage cheese and processed cheese are all fine, pasteurised or not, because they are not the kind that supports listeria growth.
• Freezing cured meat for four days at −18°C kills toxoplasma and makes parma ham and salami acceptable to eat cold, which is a useful workaround.
• If you have already eaten something on the list, the overwhelming likelihood is that nothing will happen. Speak to your midwife rather than worrying alone.
• The same broad principles apply to other vulnerable groups — older people, babies and anyone immunocompromised — though the specific lists differ.

Common mistakes

• Avoiding all soft cheese — The concern is mould-ripened and soft blue cheeses, not soft cheese generally. Cream cheese, cottage cheese, mozzarella, ricotta, halloumi and feta are all fine, and unnecessary avoidance narrows the diet at exactly the time it should not be narrowed.
• Assuming pasteurised makes any cheese safe — Pasteurisation deals with the milk, but mould-ripened cheeses have a moisture and pH profile that lets listeria grow afterwards. That is why pasteurised brie is still on the list.

Questions people ask