Most foods can be enjoyed during pregnancy but some should be avoided or treated with caution:
Liver and liver products
Although liver and liver products, such as pâté and liver sausage, provide iron and folate, they also contain high concentrations of vitamin A.
A typical 100g portion contains 13,000-40,000µg of vitamin A, which is over 18 times the RNI for pregnant women.
Too much vitamin A may be harmful to a developing baby in the first three months of pregnancy.
As a result, the Department of Health advises all pregnant women and women planning a pregnancy to avoid foods or supplements which contain high levels of vitamin A such as liver, liver sausage, liver pâté and cod liver oil.
It is not necessary to avoid other foods with vitamin A, such as whole milk, cheese, oily fish, eggs, and fortified margarine or foods with beta-carotene (a precursor form of vitamin A) such as red and orange fruits and vegetables, and green leafy vegetables.
All types of pâté should be avoided during pregnancy as they may occasionally contain harmful bacteria called Listeria which are responsible for listeriosis.
Although listeriosis causes only mild flu-like symptoms in the mother, it can severely affect the developing baby and may result in miscarriage, still-birth or severe illness in the newborn child.
Mould-ripened soft cheeses (e.g. Brie, Camembert) and cheese with blue veins (e.g. Stilton, Danish Blue) may also occasionally contain listeria so should be avoided.
However, there is no risk from hard cheeses (such as Cheddar) which are good sources of calcium and cottage cheese, cream cheese and processed cheese.
Raw and lightly cooked eggs
Raw and lightly cooked eggs (and dishes containing raw eggs e.g. home-made mayonnaise, mousse and ice-cream) are best avoided during pregnancy as there is a risk they may contain salmonella bacteria, which can cause food poisoning.
Shark, swordfish and marlin
Pregnant women (and those trying to conceive) should not eat shark, swordfish or marlin and should limit tuna to no more than two portions of fresh tuna per week or four medium-size cans a week (this equates to about twelve rounds of tuna sandwiches or six tuna salads).
These types of fish have been found to contain methylmercury, which may be harmful to an unborn baby's nervous system.
Undercooked, chilled ready meals
It is important to make sure cooked, chilled ready meals are re-heated thoroughly until piping hot as this will destroy any listeria that may be present.
Raw poultry and raw meat
Toxoplasmosis is a rare illness caused by a parasite occasionally found in raw meat.
It can be harmful to unborn babies (may cause blindness and metal retardation), so pregnant women should avoid raw and undercooked meat.
The toxoplasmosis parasite may also be present in cat faeces so it is advisable for pregnant women to wear rubber gloves when disposing of cat litter.
Cooking poultry and meat thoroughly will also reduce the risk of salmonella.
Raw shell fish
Raw shell fish sometimes contains harmful bacteria or viruses that can cause food poisoning.
All unpasteurised milk including cows', goats' and sheep's milk should be avoided.
Goats’ milk should be avoided due to the risk of toxoplasmosis.
It is a good idea to avoid alcohol completely when planning a baby and in the early stages of pregnancy but there is little evidence to suggest total avoidance is necessary once pregnancy is established.
However, pregnant women should be warned against regular or heavy drinking and should limit themselves to no more than 1 or 2 units of alcohol, once or twice a week.
One unit of alcohol is a small (125ml) glass of wine, half a pint of standard-strength beer, lager or cider, or a single pub measure (25ml) of spirit.
In some countries (USA, Canada and Australia) complete abstinence from alcohol is recommended.
Although there is no need to avoid caffeine-containing food and drink altogether, pregnant women are advised to limit their consumption to no more than 300mg/day - roughly equivalent to 4 cups of instant coffee (190ml cup), 6 cups of tea (190ml cup), 8 cans of cola (330mls) or 6 bars of plain chocolate (50g). The caffeine content of milk chocolate is about half that of plain chocolate.
This is because high levels of caffeine have been linked to low birth weight and miscarriage.
If you would like to eat peanuts or foods containing peanuts (such as peanut butter) during pregnancy or whilst breastfeeding, you can choose to do so as part of a healthy balanced diet, unless you yourself are allergic to them.
Previous advice was that women may wish to avoid eating peanuts during pregnancy or whilst breastfeeding if there was a history of allergy in their immediate family (such as asthma, eczema, hayfever, food allergy or other types of allergy). This advice has changed because the latest research has shown that it isn't clear that eating or not eating peanuts (or foods containing peanuts) during pregnancy or whilst breastfeeding affects the chances of your baby developing a peanut allergy.
Common food-related problems during pregnancy
Nausea and morning sickness
Nausea and morning sickness are common symptoms in early pregnancy.
This may be due to hormonal changes, and a variety of triggers such as smells of foods, perfume and cigarette smoke.
Many women find that eating small high carbohydrate snacks at frequent intervals (e.g. 2-3 hourly) rather than three large meals a day helps.
Indigestion and heartburn
Indigestion and heartburn is very common and can start as early as the third month but is generally worst in last months of pregnancy.
Again, small frequent snacks often help lessen symptoms, as do avoiding spicy and fatty foods and eating slowly.
Constipation, which sometimes occurs in late pregnancy, can be eased by eating more foods containing fibre (e.g. wholemeal bread and cereals, fruit, pulses and vegetables) and drinking plenty of fluid (six to eight glasses per day).
Regular, gentle exercise can also help.
During the early months, many pregnant women experience food cravings or avoid certain foods they normally enjoy.
Provided there is no drastic dietary change (e.g. leaving out an entire food group) there is unlikely to be any adverse effect on the mother’s health.
Pica is the craving for and ingestion of substances which are usually considered inedible for human consumption.