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Diet and Lifestyle during Pregnancy

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Pregnancy can be a very exciting time for most people. It can also make some people feel anxious about what they should (or should not) be doing for their own and their baby's health. The information below will answer many frequently asked questions. There are also links to further reliable sources of information at the bottom of the page.

During pregnancy it is important to continue to eat a healthy balanced diet. You may have an increased appetite but it is not necessary to 'eat for two', even if you are having twins or triplets. Too much weight gain increases your risk of developing problems later in the pregnancy. Also, extra weight is difficult to lose after the birth. According to the World Health Organization, for women with a normal pre-pregnancy weight, a weight gain of 10-14 kg over the pregnancy is associated with the lowest risk of pregnancy complications.

Eat a healthy balanced diet

Aim to eat a healthy diet (which everyone should be eating, not just pregnant women). Briefly, a third of most meals should be starch-based foods (such as bread, cereals, potatoes, rice, and pasta), with fruit and vegetables. Eat protein foods such as meat, fish, pulses, chicken, etc, in moderation.

Include foods with plenty of iron, calcium and folic acid: a growing baby needs these nutrients right from the start of the pregnancy:

  • Iron is mainly in red meat, pulses, dried fruit, green vegetables and fortified cereals.
  • Calcium is mainly in dairy products such as milk, cheese, and yoghurt. (Low-fat milk, cheeses and yoghurts usually contain just as much calcium as the full-fat varieties.)
  • Folic acid is mainly in green vegetables, brown rice, and fortified cereals.

Fish: in general, fish is a good source of protein and other nutrients. Aim to eat at least two portions of fish per week, with at least one portion being oily fish (see below). However, there are some important exceptions. Some types of fish contain a high level of mercury which can damage the developing nervous system of an unborn baby. Because of this, the Food Standards Agency (FSA) advises:

  • You should not eat any shark, marlin, or swordfish.
  • Limit tuna - eat no more than four medium-sized cans (drained weight = 140 g per can) or two fresh tuna steaks per week (weighing about 140 g cooked or 170 g raw).

Also, do not eat raw fish or uncooked shellfish (which may contain germs (bacteria), viruses or parasites).

Also, some types of fish may contain a small amount of chemicals from pollution, including dioxins and polychlorinated biphenyls (PCBs). If you eat a lot of these fish, these chemicals may build up in your body over time, which may be harmful. Because of this, the FSA advises that you should have no more than two portions a week of any of the following fish:

  • Oily fish, including mackerel, sardines, salmon, trout and fresh tuna. (Tinned tuna doesn't count as oily fish.)
  • Sea bream, sea bass, turbot, halibut, rock salmon (also known as dogfish, flake, huss, rig or rock eel).
  • Brown crabmeat.

However, the advice above (from the FSA) is controversial. Some experts think the advice to eat no more than two portions of oily fish per week during pregnancy is too restrictive, and may even be detrimental to a developing baby. For example, one study found that children of mothers who had eaten a reasonable amount of oily fish during pregnancy had, on average, better communication and social skills at age 7. Oily fish are rich in nutrients called omega-3 fatty acids. It is thought that omega-3 fatty acids are important to aid brain development and may be the reason for the results of this study.

Therefore, some experts argue that the concern over toxic chemicals in fish is over-cautious and that the benefits of eating three or more portions of oily fish per week outweigh other risks. Further research may help to clarify this.

Foods and drinks to avoid

You should not eat the following if you are pregnant:

  • Anything with a lot of vitamin A. You need a small amount of vitamin A to keep healthy. However, large amounts can harm an unborn baby. So, avoid:
    • Liver and liver products such as liver pâté and cod liver oil supplements.
    • Vitamin tablets or supplements which contain vitamin A.
  • Food which may have high levels of listeria. This bacterium (germ) does not usually cause problems in people who are not pregnant. However, pregnant women are more likely to become infected with listeria, and it sometimes causes miscarriage, stillbirth, or infections in the baby after birth. Foods which are most at risk of carrying listeria are:
    • Undercooked meats and eggs. This may occur in some pre-cooked meats and pre-prepared meals. Make sure all meat foods are cooked until piping hot. Eggs should be cooked until the white and yolk are solid. Avoid foods that may contain raw eggs, such as some types of mayonnaise and mousse.
    • Mould-ripened and soft cheeses such as brie, Camembert and blue-veined cheeses. (Hard cheeses and processed cottage cheese are safe.)
    • Pâtés - including vegetable pâtés.
    • Raw shellfish and raw fish.
    • Unpasteurised milk. Note: goat's milk is often unpasteurised, and goat's milk products such as cheeses are often made from unpasteurised milk.
  • Certain fish (as described earlier).
  • Limit the amount of caffeine to no more than 200 mg per day. Caffeine is a substance that occurs naturally in foods such as tea, coffee and chocolate; is added to some drinks such as cola, and some energy drinks; and is an ingredient of some cough and cold remedies, and some painkillers which you can buy at pharmacies. Having a lot of caffeine increases your risk of having a miscarriage and a baby with low birth weight. The increased risk is small. But, it is best to play safe.The main sources of caffeine are coffee, tea, chocolate, and cola. It is also added to some energy drinks and to some cough and cold remedies. As a rough guide:
    • One mug of instant coffee has about 100 mg of caffeine.
    • One mug of brewed coffee has about 140 mg of caffeine.
    • One mug of tea has about 75 mg of caffeine.
    • One 50 g plain chocolate bar has about 50 mg of caffeine. Milk chocolate has about half the caffeine that plain chocolate has.
    • One can of cola or half a can of an energy drink has up to 40 mg of caffeine.
  • Liquorice may be important to avoid. A research study published in 2009 found that women who ate a lot of liquorice (which is common in some countries) were more likely to have children with lower intelligence levels and more behavioural problems. Further research is needed to clarify this issue.

A note about peanuts: until recently, the FSA advised that you may wish to avoid eating peanuts when you are pregnant if you have an atopic disease such as asthmaeczema, or hay fever, or if a close family member has one of these conditions. This was because there was a concern that children could develop a peanut allergy as a result of their mother eating peanuts during pregnancy. However, in the light of new evidence, this advice was changed in December 2008. The FSA now advises that there is no need for women who are pregnant or breast-feeding, or who have children aged under 3, to change their diets in order to exclude peanuts.


The effects of some prescribed medicines have been well studied and it is known that certain medicines are safe in pregnancy. For example, paracetamol at normal dose is safe and useful for headaches, backache and other aches and pains that may occur during pregnancy. However, for many medicines, we do not know for sure if they are safe or unsafe. So if you are pregnant, you should minimise your use of medication. This includes medicines that you can buy. Also, just because a medicine says it is herbal or natural, it does not necessarily mean that it is harmless or safe.

Always tell a doctor or dentist who prescribes medication for you that you are pregnant. Also, don't take medicines that you can buy over the counter (including herbal remedies) unless they are known to be safe in pregnancy. The pharmacist will advise.

  • Paracetamol at normal dose is safe and useful for headaches, backache, and other aches and pains that may occur during pregnancy.
  • Anti-inflammatory painkillers such as ibuprofen. You should not normally take these during pregnancy. Regular use during pregnancy may affect the large blood vessels of the developing baby.
  • Laxatives. Constipation is common in pregnancy and you may need a laxative. At first it is best to try increasing the fibre in your diet and increasing the amount of non-alcoholic fluids that you drink. If this fails then fibre supplements such as bran, ispaghula and sterculia are safe. If you need something stronger, then it is best to discuss this with a doctor. Some laxatives such as docusate and lactulose may be prescribed safely for a short time.
  • Antihistamines. The safest one to use in pregnancy is chlorphenamine. This is because it is the oldest, and so has a long-established safety record. However, it tends to make some people drowsy. If you require an alternative then it is best to see a doctor for advice.
  • Decongestants such as pseudoephedrine, phenylephrine and xylometazoline are best avoided in the early stages of pregnancy. However, they are unlikely to be harmful if used just now and then.

If you already take regular medication, (for example, for epilepsy or diabetes), it is important that you discuss this with a doctor before becoming pregnant. If you have an unplanned pregnancy, discuss with your doctor as early as possible any medication that you take. In some cases, the risk of taking the medicine has to be balanced against the risk of not taking the medicine, and your condition not being treated.

Vitamins and supplements

Folic acid: you should take folic acid tablets (supplements). Ideally, do this from at least one month before you get pregnant, and continue taking them until at least the end of the 12th week of pregnancy - even if you are healthy and have a good diet. Folic acid is a naturally occurring vitamin found in spinach, sprouts, broccoli, green beans, and potatoes. Some bread and breakfast cereals are fortified with folic acid. However, you need a good supply of folic acid when you are pregnant to help with the development of the baby. If you take folic acid tablets in early pregnancy you reduce the risk of having a baby born with a spinal cord problem such as spina bifida. There is evidence that folic acid also reduces the risk of having a baby born with a cleft lip and palate, a heart defect (congenital heart disease), and the risk of a premature (preterm, 'prem' or early) labour.

You can buy folic acid tablets from pharmacies. Also, the NHS Healthy Start scheme provides vitamin supplements that contain folic acid. These are free to many women who are on certain benefits - see:

  • For most women, the dose is 400 micrograms (0.4 mg) a day.
  • If you have an increased risk of having a child with a spinal cord problem then the dose is 5 mg a day. You need a prescription for this higher dose - that is, if:
    • You have had a previously affected pregnancy.
    • You or your partner have (or have a family with) a spinal cord defect.
    • You are taking medication for epilepsy.
    • You are obese - especially if your body mass index (BMI) is 30 or more.
    • You have coeliac disease, diabetes, sickle cell anaemia, or thalassaemia.

Ideally, start taking folic acid tablets before becoming pregnant. The common advice is to start from the time you stop using contraception. If the pregnancy is unplanned then start taking folic acid tablets as soon as you know that you are pregnant. However, a recent study looked at the effect of taking folic acid for a year prior to becoming pregnant. This study looked at the effect folic acid had on reducing preterm labour and delivery of the baby (that is, of having a 'prem' baby). The study found a significant decrease in the rate of preterm delivery for women who took folic acid for one year prior to becoming pregnant. So, you may wish to consider taking folic acid tablets well before you plan to become pregnant.

Because of the substantial benefits of folic acid, some countries routinely fortify staple foods, such as wheat, cornflour, or rice, with folic acid. Currently there is debate as to whether the UK should follow suit and fortify certain common foods with folic acid. Many foods contain folic acid, including vegetables such as spinach, sprouts, broccoli, green beans, and potatoes. Some bread and breakfast cereals are fortified with folic acid. However, the intake for each individual can vary.

Vitamin D supplements: vitamin D is needed for growth and supplements are recommended for all pregnant women, breast-feeding women and breast-fed babies. The dose if you are pregnant or breast-feeding is 400 units (10 micrograms) daily. Some experts think that women who get little or no sunshine on their skin need a higher dose, such as 800 units (20 micrograms) daily. This is because most of the vitamin D that we get is made in the skin with the help of sunlight. Your doctor will advise. Pregnant women can get free prescriptions and vitamins.

Iodine: a research study published in 2011 concluded that it is likely that many young women in the UK do not get enough iodine in their diet and are lacking in iodine. Iodine mainly comes from milk, yogurt, eggs and fish. Because iodine intake can be variable, some countries routinely fortify cereals and bread with iodine - but not the UK. Iodine is essential for the brain development of a baby in the womb (uterus). The research author's concern is that many pregnant women will be lacking in iodine. This may cause their baby to have reduced brain development and be less intelligent than they would otherwise have been. Further research is needed in this area. But, in the meantime, you may wish to consider whether your diet has enough iodine. And, if it doesn't, perhaps talk to your doctor about taking an iodine supplement. A link to the NHS analysis on this study is given at the end.


If you smoke and you are pregnant, you are strongly advised to stop smoking. This is to benefit your health, and the health of your baby. Tobacco smoke contains poisonous chemicals which pass into your bloodstream when you smoke, and then on into the the growing baby's blood. Smoking when you are pregnant increases the risk of miscarriage, slow growth of the baby leading to a low birth weight, premature labour and stillbirth. Even after the birth, children of smoking parents have an increased risk of developing chest infections, asthma, glue ear, and cot death (sudden infant death syndrome).

You and your baby will get most benefit, and the risks will be most reduced, if you stop before you become pregnant. Planning to become pregnant is a good incentive to stop smoking for many women, and is often a good time to persuade partners to give up too. However, your baby will still gain some benefit if you stop at any point during pregnancy.

For many people it is not easy to stop. Below are some tips which may help:

  • Write a list of all the reasons why you want to stop, and keep them with you. Refer to them when you are tempted to light up.
  • Set a date for stopping, and stop completely. (Some people prefer the idea of cutting down gradually. However, research has shown that if you smoke fewer cigarettes than usual, you are likely to smoke more of each cigarette, and nicotine levels remain nearly the same. Therefore, it is usually best to stop once and for all from a set date.)
  • Tell everyone. Friends and family often give support and may help you.
  • Get rid of ashtrays, lighters, and all cigarettes.
  • Be prepared for some withdrawal symptoms. When you stop smoking, you are likely to get symptoms which may include: nausea (feeling sick), headaches, anxiety, irritability, craving, and just feeling awful. These symptoms are caused by the lack of nicotine that your body has been used to. They tend to peak after 12-24 hours, and then gradually ease over 2-4 weeks.
  • Be aware of situations in which you are most likely to want to smoke (for example, the pub). Try changing your routine for the first few weeks. If drinking tea and coffee are difficult times, try drinking mainly fruit juice and plenty of water.
  • Take one day at a time. Mark off each successful day on a calendar. Look at it when you feel tempted to smoke, and tell yourself you don't want to start all over again.
  • Be positive. You can tell people that you don't smoke. You will smell better. After a few weeks you should feel better, taste your food more, and cough less. You will have more money.
  • Food. Some people worry about gaining weight when they give up smoking, as the appetite may improve. Anticipate an increase in appetite, and try not to increase fatty or sugary foods as snacks. Try sugar-free gum and fruit instead.
  • Don't despair if you fail and have a cigarette. You don't have to start smoking again. Pick yourself up and try again. Examine the reasons why you felt it was more difficult at that particular time. It will make you stronger next time.

There are also medicines available to help you quit.

Nicotine replacement therapy (NRT): this can help if withdrawal symptoms are troublesome. Nicotine gum, sprays, patches, tablets, lozenges, and inhalers are available to buy, and on prescription. Using one of these increases your chance of stopping smoking if you really want to stop. A pharmacist, GP, or practice nurse can advise about NRT. 

If you are pregnant, you can consider using NRT. NRT is a medicine and may have effects on the baby. But, many people argue that NRT is safer than smoking as, unlike smoking, NRT just gives you nicotine. Smoking gives you nicotine plus a lot of toxic chemicals. So, if NRT does enable you to stop smoking, it may be worthwhile to take it even if you are pregnant.

There are other medicines available but these can only be used BEFORE you become pregnant. They are called bupropion (trade name Zyban®) and varenicline (trade name Champix®). You should not take these medicines when you are pregnant, as the risk to the unborn child is not known.

GPs, practice nurses, or pharmacists can provide information, encouragement, and tips on stopping smoking. Also, throughout the country there are specialist NHS Stop Smoking Clinics which have good success in helping people to stop smoking. Your doctor may refer you to one if you are keen to stop smoking.


Women who are pregnant should not drink alcohol. The reason for this is that alcohol can cause damage to a developing baby. Alcohol gets to a baby through the placenta if a pregnant woman drinks alcohol. A baby cannot process alcohol very well. So, any alcohol in your baby stays in their body much longer than in you. This is known to be a risk for causing serious problems. For example, studies have shown that:

  • Pregnant women who drink more than 15 units a week have an increased risk of having a baby with a low birth weight.
  • Pregnant women who drink more than 20 units a week have an increased risk of having a baby with some damage to the brain, causing impaired intellect.
  • Pregnant women who drink very heavily risk having a baby with fetal alcohol syndrome. Babies with this syndrome have brain damage, a low birth weight and facial malformations.

However, there has been debate over the years as to whether small amounts of alcohol are safe to drink during pregnancy. Also, if there is a time of pregnancy when alcohol is most likely to cause harm. But, recent research supports the advice of not drinking any alcohol whilst pregnant. 

For the sake of your baby's health if you are already dependent on alcohol, you should be open and honest about the amount you drink. Once you are pregnant, many different people may offer you support, including doctors, midwives, social workers and counsellors. This can become confusing but, if you regularly keep in touch with one healthcare professional (usually your midwife or GP), they should be able to make sure that you are not bombarded with too many unnecessary appointments.

Note: one unit of alcohol is in about half a pint of beer, or two thirds of a small glass of wine, or one small pub measure of spirits. See separate leaflet called Alcohol and Sensible Drinking for details.


For most women, it is important to do some regular physical activity during pregnancy as part of living a healthy lifestyle. In most cases, moderate physical activity during pregnancy is safe and can have benefits for both you and your baby and should not harm either of you. However, you do need to be sensible about what type of physical activity you do. You should aim to do a mixture of both aerobic physical activity and muscle-strengthening physical activity. In general, at least 30 minutes of physical activity every day is recommended. Physical activity during pregnancy is safe for most women. However, there are some pregnant women who should speak to their doctor or midwife before doing any physical activity during their pregnancy. See the separate leaflet called Pregnancy and Physical Activity for further information.


Sex is safe for most couples during pregnancy. The penis will go no further than your vagina and the baby will be unaffected. Later in pregnancy, sex and orgasm may provoke contractions known as Braxton-Hicks contractions. These make your bump feel hard. They can be uncomfortable but are quite normal. They usually pass after a few minutes.

Your doctor or midwife may advise you to avoid sex if you have had heavy bleeding in your pregnancy. This may also be the case if your waters have broken. This is because the protective barrier has gone, so having sex then may increase the risk of infection. 

As the pregnancy progresses and the bump becomes bigger you may find some positions more difficult. You and your partner may need to experiment to find something that works for both of you. 

Working during pregnancy

If you think that your job may pose a risk to a pregnancy, then ideally you should discuss this with your employer before you become pregnant or as soon as you become pregnant.

Certain jobs and workplaces may pose a risk to a pregnancy, in particular to the early stages of pregnancy. For example:

  • Raw meat is sometimes contaminated with germs (bacteria), such as listeria and toxoplasma. If these germs infect adults, they may cause listeriosis or toxoplasmosis, but may cause little harm. However, these germs can cause serious problems to your unborn child if you become infected when you are pregnant.
  • If you work with certain animals. For example:
    • You should avoid contact with sheep and lambs at lambing time. This is because some lambs are born contaminated with germs such as listeria, toxoplasma and chlamydia which may affect you and your unborn baby.
    • Cats and kittens often carry toxoplasma germs. Especially cat poo (faeces). So, cleaning out cat litters and handling cats and kittens can be a risk.
  • If your job puts you at risk of contracting hepatitis B, you should be immunised against this virus. For example, if you are a healthcare worker, or work at a daycare or residential centre. (Women with hepatitis B can pass on the infection to their child at childbirth.)
  • If you work with chemicals, fumes, radiation, etc. Some may be toxic to an unborn baby.

The above are just examples. In short, if you think that your occupation may pose a risk to a pregnancy then you should discuss this with your employer before becoming pregnant. A change in job, or working practice, may be necessary.

You and your employer may wish to download information guides from the Health and Safety Executive (HSE) website at

Street (illicit) drugs

The effects of all the different types of street drugs on pregnancy are not fully known. However, it is safe to assume that if you use street drugs, it is likely to pose a risk to the unborn child. A couple of examples of what is known include:

  • If you take or inject heroin when you are pregnant it increases the risk of:
    • Miscarriage.
    • Slowing the growth of the baby, leading to a low birth weight.
    • Premature labour, leading to the baby being premature ('prem').
    • Stillbirth.
    • The baby having withdrawal symptoms after the birth.
  • Using cocaine when you are pregnant is particularly hazardous. It increases the risk of:
    • Serious life-threatening bleeding from the uterus in late pregnancy (placental abruption).
    • Miscarriage.
    • Slowing the growth of the baby, leading to a low birth weight.
    • Premature labour leading to the baby being 'prem'.
    • Stillbirth.
    • Possibly, abnormalities of the baby when it is born.

But the above are just two examples. There are many street drugs and it is beyond the scope of this leaflet to discuss each drug in turn. But, you can contact FRANK (details below) for information about individual drugs.

If you intend to become pregnant you should aim to stop taking or using street drugs. It is best to postpone the pregnancy until you are off drugs.

If you have an unplanned pregnancy you should aim to stop the drugs as soon as possible.

Some people can stop drugs without any help, but many people will require help. If you cannot come off drugs easily, see your doctor for help. Your doctor will be able to refer you to a local community drug team for help.

Most community drug teams can:

  • Offer treatment plans. For example, one option for people who use heroin is to take substitute therapy with methadone in place of injecting heroin. This option is safer than injecting heroin during pregnancy.
  • Provide counselling and information.
  • Provide harm-reduction activities such as needle exchange schemes.


Avoid contact with sheep and lambs at lambing time. This is because some lambs are born carrying the germs that cause listeriosis, toxoplasmosis and chlamydia. These may be passed on to you and your unborn baby. Toxoplasma is also found in cat poo. You should always wash your hands after handling cats and kittens and ask someone else to wash out cat litter trays.

Original Author:
Dr Hayley Willacy
Current Version:
Peer Reviewer:
Dr John Cox
Document ID:
28461 (v1)
Last Checked:
Next Review:
The Information Standard - certified member
See also: Antenatal Infections and their Consequences written for professionals
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