Nhs advice:
What you can eat
- cooked fish and seafood
- sushi, as long as the fish has been cooked thoroughly
- cooked shellfish, such as mussels, lobster, crab, prawns, scallops and clams
What to limit
- you should eat no more than 2 portions of oily fish a week, such as salmon, trout, mackerel or herring
- you should eat no more than 2 tuna steaks (about 140g cooked or 170g raw) or 4 medium-size cans of tuna (about 140g when drained) per week
Information:
Tuna does not count as an oily fish
You can have 2 tuna steaks, or 4 medium-size cans of fish, as well as 2 portions of oily fish a week.
What to avoid
- swordfish
- marlin
- shark
- raw shellfish
cold-smoked or cured fish (for example smoked salmon or gravlax, including in sushi), unless it has been cooked until steaming hot
Why
You should avoid ready-to-eat cold-smoked or cured fish because it could be contaminated with listeria bacteria. These bacteria can cause an infection called listeriosis, which can lead to miscarriage or stillbirth, or make your newborn baby seriously ill. Cooking smoked or cured fish until it's steaming hot will kill any bacteria that may be present.
You should limit tuna because it has more mercury in it than other fish. If you eat too much mercury, it can be harmful to your unborn baby.
You should limit oily fish because they can have pollutants such as dioxins and polychlorinated biphenyls in them. If you eat too much of these, they can be harmful to your unborn baby.
You should avoid raw shellfish because they can have harmful bacteria, viruses or toxins in them. These can make you unwell and give you food poisoning.