Foods to avoid in pregnancy

You can have 2 tuna steaks, or 4 medium-size cans of fish, as well as 2 portions of oily fish a week.

Causes – Miscarriage

If a miscarriage happens during the first trimester of pregnancy (the first 3 months), it’s usually caused by problems with the unborn baby (foetus). About 3 in every 4 miscarriages happen during this period.

If a miscarriage happens after the first trimester of pregnancy, it may be the result of things like an underlying health condition in the mother.

These late miscarriages may also be caused by an infection around the baby, which leads to the bag of waters breaking before any pain or bleeding. Sometimes they can be caused by the neck of the womb opening too soon.

First trimester miscarriages

First trimester miscarriages are often caused by problems with the chromosomes of the foetus.

Chromosome problems

Chromosomes are blocks of DNA. They contain a detailed set of instructions that control a wide range of factors, from how the cells of the body develop to what colour eyes a baby will have.

Sometimes something can go wrong at the point of conception and the foetus receives too many or not enough chromosomes. The reasons for this are often unclear, but it means the foetus will not be able to develop normally, resulting in a miscarriage.

This is very unlikely to recur. It does not necessarily mean there’s any problem with you or your partner.

Placenta problems

The placenta is the organ linking your blood supply to your baby’s. If there’s a problem with the development of the placenta, it can also lead to a miscarriage.

Things that increase your risk

An early miscarriage may happen by chance. But there are several things known to increase your risk of problems happening.

Your age can also have an influence:

• in women under 30, 1 in 10 pregnancies will end in miscarriage
• in women aged 35 to 39, up to 2 in 10 pregnancies will end in miscarriage
• in women over 45, more than 5 in 10 pregnancies will end in miscarriage

A pregnancy may also be more likely to end in miscarriage if you:

• are obese
• smoke
• use drugs
• drink lots of caffeine
• drink alcohol

Second trimester miscarriages

Long-term health conditions

Several long-term (chronic) health conditions can increase your risk of having a miscarriage in the second trimester, especially if they’re not treated or well controlled.

• diabetes (if it’s poorly controlled)
• severe high blood pressure
• lupus
• kidney disease
• an overactive thyroid gland (hyperthyroidism)
• an underactive thyroid gland (hypothyroidism)
• antiphospholipid syndrome (APS)

Infections

The following infections may also increase your risk:

Food poisoning

Food poisoning, caused by eating contaminated food, can also increase the risk of miscarriage. For example:

• listeriosis – most commonly found in unpasteurised dairy products, such as blue cheese
• toxoplasmosis – which can be caught by eating raw or undercooked infected meat
• salmonella – most often caused by eating raw or partly cooked eggs

Medicines

Medicines that increase your risk include:

• misoprostol – used for stomach ulcers
• retinoids – used for eczema and acne
• methotrexate – used for conditions such as rheumatoid arthritis
• non-steroidal anti-inflammatory drugs (NSAIDs) – such as ibuprofen; these are used for pain and inflammation

To be sure a medicine is safe in pregnancy, always check with your doctor, midwife or pharmacist before taking it.

Womb structure

Problems and abnormalities with your womb can also lead to second trimester miscarriages. Possible problems include:

• non-cancerous growths in the womb called fibroids
• an abnormally shaped womb

Weakened cervix

In some cases, the muscles of the cervix (neck of the womb) are weaker than usual. This is known as a weakened cervix or cervical incompetence.

A weakened cervix may be caused by a previous injury to this area, usually after a surgical procedure. The muscle weakness can cause the cervix to open too early during pregnancy, leading to a miscarriage.

Polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a condition where the ovaries are larger than normal. It’s caused by hormonal changes in the ovaries.

PCOS is known to be a leading cause of infertility as it can prevent the release of an egg (ovulation). There’s some evidence to suggest it may also be linked to an increased risk of miscarriage.

Misconceptions about miscarriage

An increased risk of miscarriage is not linked to:

• your emotional state during pregnancy, such as being stressed or depressed
• having a shock or fright during pregnancy
• exercise during pregnancy – but discuss with your GP or midwife what type and amount of exercise is suitable for you during pregnancy
• lifting or straining during pregnancy
• working during pregnancy – or work that involves sitting or standing for long periods
• having sex during pregnancy
• travelling by air
• eating spicy food

Recurrent miscarriages

If you have had a miscarriage, it’s natural to worry that you’ll have another if you get pregnant again. But most miscarriages are a one-off event.

About 1 in 100 women experience recurrent miscarriages (3 or more in a row) and many of these women go on to have a successful pregnancy.

Page last reviewed: 09 March 2022
Next review due: 09 March 2025

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Foods to avoid in pregnancy

There’s a small chance that unpasteurised or soft ripened dairy products may contain Listeria bacteria. This can cause an infection called listeriosis.

Listeriosis can lead to miscarriage or stillbirth, or make your newborn baby very unwell.

Soft cheeses with a white coating on the outside have more moisture. This can make it easier for bacteria to grow.

Cooking cheese until it’s steaming hot kills bacteria, reducing the risk of listeriosis.

Meat and poultry

What you can eat

• meats such as chicken, pork and beef, as long as they’re well-cooked with no trace of pink or blood; be especially careful with poultry, pork, sausages and burgers
• cold, pre-packed meats such as ham and corned beef

What to be careful with

• cold cured meats, such as salami, pepperoni, chorizo and prosciutto (unless cooked thoroughly)

What to avoid

• raw or undercooked meat
• liver and liver products
• all types of pâté, including vegetarian pâté
• game meats such as goose, partridge or pheasant

Why

There’s a small risk of getting toxoplasmosis if you eat raw and undercooked meat, which can cause miscarriage.

Cured meats are not cooked, so they may have parasites in them that cause toxoplasmosis.

Liver and liver products have lots of vitamin A in them. This can be harmful to an unborn baby.

Game meats may contain lead shot.

What you can eat

• raw, partially cooked and fully cooked British Lion hen eggs (they have a lion stamp on them) and hen eggs produced under the Laid in Britain scheme
• foods made with raw hen egg, such as mousse and mayonnaise, if made with British Lion eggs or hen eggs produced under the Laid in Britain scheme
• well cooked eggs (white and yolk) from any hen eggs that are not British Lion eggs or produced under the Laid in Britain scheme
• well cooked eggs (white and yolk) of all other eggs, including duck, goose or quail

What to avoid

• raw or partially cooked hen eggs that are not British Lion or produced under the Laid in Britain scheme
• raw or partially cooked duck, goose or quail eggs

Why

British Lion hen eggs and hen eggs produced under the Laid in Britain scheme are less likely to have salmonella in them.

Salmonella is unlikely to harm your unborn baby, but you could get food poisoning.

You should cook all eggs thoroughly, unless they are British Lion hen eggs or hen eggs produced under the Laid in Britain scheme.

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.

Other foods and drinks

Caffeine

You can have caffeine, but no more than 200mg per day. Regularly drinking more than this amount can increase your risk of pregnancy complications, such as low birthweight, and even miscarriage.

• 100mg in a mug of instant coffee
• 140mg in a mug of filter coffee
• 75mg in a mug of tea (green tea can have the same amount of caffeine as regular tea)
• 40mg in a can of cola
• 80mg in a 250ml can of energy drink
• less than 25mg in a 50g bar of plain dark chocolate
• less than 10mg in a 50g bar of plain milk chocolate

Herbal teas

The caffeine content can vary quite widely between different brands of herbal tea. Some contain no caffeine, while others may have quite high levels.

Check the ingredients label on the packet to see how much caffeine is in a brand. Some of the herbs used in herbal tea can also be potentially dangerous if you have a lot of them during pregnancy; especially during weeks 1 to 12 (first trimester).

As a general rule, if you drink no more than 1 to 2 cups of herbal tea a day during your pregnancy, you should be fine.

Alcohol

Drinking alcohol in pregnancy can lead to long-term harm to your baby.

If you’re pregnant or planning to get pregnant, the safest approach is to not drink alcohol at all.

This keeps risks to your baby to a minimum.

Liquorice

Liquorice is safe to eat. But you should avoid liquorice root.

Fruits, vegetables and salads

Be careful with fruits, vegetables and salads as they can have soil on them, which can make you unwell.

Make sure to thoroughly wash all fruits, vegetables and salad ingredients.

Peanuts

You do not need to avoid eating peanuts when you’re pregnant.

Only avoid eating peanuts if you’re advised to by a healthcare professional, or if you have a nut allergy.

Vitamins

Do not take high-dose multivitamin supplements, or any supplements with vitamin A in them.

Urgent advice: Get advice from 111 straight away if:

• you feel unwell after eating one of the foods to avoid
• you have signs of listeriosis or toxoplasmosis infection

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More in Keeping well in pregnancy

Page last reviewed: 19 May 2023
Next review due: 19 May 2026

Support links

• Home
• Health A to Z
• Live Well
• Mental health
• Care and support
• Pregnancy
• NHS services
• Coronavirus (COVID-19)

• NHS App
• Find my NHS number
• View your GP health record
• View your test results
• About the NHS
• Healthcare abroad

• Other NHS websites
• Profile editor login

• About us
• Give us feedback
• Accessibility statement
• Our policies
• Cookies