Food poisoning : Pregnant women should be careful not to expose themselves to any risk of food poisoning, which is potentially very dangerous to the unborn baby, especially in the case of listeriosis and toxoplasmosis.

If you follow the guidelines below, your risk of food poisoning will be low:

	Always wash your hands before preparing food.
	Keep kitchen surfaces, cooking utensils, tea towels and so on scrupulously clean.
	Store cooked and ready-to-eat food in separate containers and shelves in the fridge; don't let juices from raw or thawing meat or fish drip onto other foods.
	Use separate chopping boards for preparing meat or poultry, and fruit and vegetables.
	Wash fruit and vegetables thoroughly to remove dirt and soil.
	Never eat food that has passed its use-by or expiration date.
	Cook food thoroughly and according to manufacturers' instructions.
	Cool leftover food quickly and use within 24 hours.
	Wash your hands carefully after touching any animals.

Listeriosis is a rare flu-like illness caused by the bacteria listeria monocytogenes. In pregnancy it may cause miscarriage, stillbirth or severe illness in the newborn baby. Pregnant women are advised to avoid those foods where high levels of the bacteria are occasionally found: paté, prepared salads such as potato or coleslaw, and soft and blue-veined cheeses such as brie, camembert and stilton. There is no risk associated with hard cheeses such as cheddar or with cottage cheese, processed cheese or cheese spread.

Toxoplasmosis is an illness caused by a parasite found in cat faeces, raw meat, soil on vegetables and, occasionally, goats' milk. In rare cases it can be passed on to the unborn baby, resulting in a range of problems, some of them serious. As a safeguard, pregnant women shouldn't eat raw or undercooked meat, unpasteurised goats' milk or cheese, or unwashed raw fruit and vegetables. Good food hygiene practices should be followed with pets too: contact with cat litter trays or soil that may have been fouled by cats should be avoided. If this isn't possible, make sure you wear gloves.

Salmonella poisoning isn't likely to have a direct adverse effect on the baby, but it is best avoided. As a precaution, steer clear of foods containing raw or lightly cooked eggs (eg, homemade mayonnaise, some sauces and mousses). Eggs dishes should be cooked until both the white and yolk are solid. Raw meat and chicken can also be a source of salmonella, so make sure all meat - and especially poultry - is thoroughly cooked. It's also important to avoid contamination of other foods by washing your hands after touching raw meat and by preventing raw meat and poultry from touching or dripping onto other food, especially that which is already cooked or will be eaten raw. Take care at parties, where food is left in warm rooms and the bacteria grow quickly.

Heavy drinking during pregnancy will harm the unborn child, and there is evidence that it's associated with birth defects and lower birth weight. Excess alcohol may also affect the mother's nutritional status by affecting or substituting for other foods.

The Department of Health advises pregnant women not to drink more than one or two units of alcohol once or twice a week, and to avoid binge drinking. In practice, many women go off the taste and smell of alcohol in early pregnancy.

From the moment you start trying to conceive until week 12 of pregnancy, you should take a daily 400mcg supplement of folic acid. Women with a history of NTDs should be prescribed a 5mg supplement.

Caffeine, found in tea, coffee and many soft drinks, interferes with your body's absorption of iron and other nutrients. Current recommendations suggest that pregnant women should have no more than 300mg of caffeine per day, which is equivalent to four cups of coffee, six cups of tea, or eight cans of cola.

Nausea and vomiting (especially in early pregnancy and not necessarily limited to the morning) affects about 70 per cent of pregnant women, and can range in severity from just feeling queasy to being unable to keep anything down. Only in around two per cent of women is the condition severe enough for medical intervention. However, check with your doctor or midwife if you are unable to keep anything down for sustained periods, as this can lead to dehydration.

	Have small meals more often - every one to two hours during the day. Base these on carbohydrate-rich foods such as bread or rolls, plain biscuits, crispbreads, oatcakes, pasta, rice or potatoes.
	Avoid fatty foods - these may be hard to digest and 'sit' heavily in your stomach.
	Take small sips of fizzy drinks - the bubbles in the drink can help alleviate the sickness.
	Stick to foods that don't take a lot of preparation.
	Keep a couple of biscuits beside your bed - it can help to nibble on a plain biscuit before you get up in the morning.
	Catch up on good days, making sure you have a variety of foods. Perhaps plan ahead and cook meals in advance to freeze.
	Try not to have too much tea and coffee. Caffeine and tannins found in these drinks can aggravate nausea and vomiting. As an alternative, try ginger and lemon tea (grated ginger and a slice of lemon); peppermint and chamomile are also very soothing.

The good news is, morning sickness generally only lasts for the first three months.

Food cravings and food aversions (powerful urges to consume or avoid particular foods) are common during pregnancy. The causes aren't fully understood; changes in the gut, hormones and heightened sense of taste and smell have all been suggested. They're unlikely to have an adverse affect, provided the overall diet is nutritionally balanced. The most common aversions are to alcohol, caffeinated drinks, fatty foods and meats.

Indigestion, heartburn and intestinal discomfort are common but, luckily, temporary problems, especially later in pregnancy when the baby displaces or squashes internal organs. Women tend to learn which foods to avoid to prevent or alleviate such problems. However, it may help to have smaller, more frequent meals, and to avoid lying down within one to two hours of eating. Some indigestion remedies available from pharmacies are suitable for pregnant women - but check before you buy.

Constipation may be alleviated by consuming foods rich in fibre and starchy carbohydrates, as well as plenty of fluids. Fibre-rich foods include breakfast cereals, wholegrain bread and rolls, wholewheat pasta, brown rice, fruit and vegetables, nuts, seeds and pulses. It's important to keep your stools soft so they can pass easily and avoid the possibility of piles. Gentle exercise also helps to keep your gut moving.

The optimum weight gain in pregnancy is 12.5kg (27lb). However, in practice different women gain different amounts and many women who don't fall within this range still go on to give birth to healthy babies. Weight gains substantially more than 12.5kg in women of normal weight before pregnancy are unlikely to reflect an increase in foetal weight, maternal lean tissue or water. Rather, the excess weight is a gain in maternal fat. Because of this, concerns have been expressed that excessive weight gain can lead to overweight and obesity. Your doctor or midwife will advise you about weight gain, but it's important that you don't 'diet' during pregnancy.

A well-planned vegetarian or vegan diet should be adequate to maintain the health of both mother and child during pregnancy. General guidelines for vegetarian diets can be found in the restricted diets section. Mothers-to-be on vegan diets that are restricted in any way should seek the help of a registered dietician for further advice.

If you have diabetes or coeliac disease and are pregnant, ask to be referred to a state-registered dietician. They will make sure your diet is well balanced to provide all the nutrients required for a healthy pregnancy.