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Advice on eating fish during pregnancy

During pregnancy, eating fish is good for your health and the development of your baby. But pregnant women should avoid some types of fish and limit the amount they eat of some others.

Avoiding raw shellfish

When pregnant, you can reduce your risk of food poisoning by avoiding raw shellfish.

Below is advice from the Scientific Advisory Committee on Nutrition and the Committee on Toxicity about eating fish when trying to get pregnant, or when pregnant or breastfeeding.

Shark, swordfish and marlin

Do not eat these if you are pregnant or trying to get pregnant. All other adults, including breastfeeding women, should eat no more than one portion per week. This is because these fish can contain more mercury than other types of fish, and this can damage a developing baby’s nervous system.

Oily fish

if you are trying for a baby, pregnant or breastfeeding, you should have no more than two portions of oily fish a week. A portion is around 140 grams.

Due to the low levels of pollutants that oily fish contain, it can build up in the body and may harm an unborn baby during a future pregnancy.

Unless your GP advises otherwise, avoid taking fish liver oil supplements when you’re pregnant or trying for a baby. These are high in vitamin A, which can be harmful to your unborn baby.

Canned tuna

If you are trying for a baby or are pregnant, you should have no more than four cans of tuna a week. This is because tuna contains higher levels of mercury than other fish. If you are breastfeeding, there is no limit on how much canned tuna you can eat.

These figures are based on a medium size can of tuna with a drained weight of around 140g per can. Remember, canned tuna doesn't count as oily fish, so you can eat this as well as your maximum two portions of oily fish.

Due to the higher levels of mercury in tuna, if you’re eating canned tuna, don’t pick fresh tuna as your oily fish.

Children and babies over six months

Children should avoid eating any shark, swordfish or marlin. This is because the levels of mercury in these fish can affect their nervous systems.

You should also avoid giving raw shellfish to babies and children to reduce their risk of getting food poisoning.

You can give boys up to four portions of oily fish a week, but it is best to give girls no more than two portions.

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