Pregnancy and diet
Good nutrition during pregnancy can help to keep you and your developing baby healthy. The need for certain nutrients, such as iron and folate, is increased at this time but only a small amount of extra energy is needed. A normal weight gain over the course of a pregnancy is around 10-13kg for women who were a healthy weight before conception.
Healthy foods for pregnant women
It is important to choose a wide variety of foods to ensure the nutritional needs of both mother and baby are met. Try to eat:
- Lots of fruit and vegetables, wholegrain breads and cereals
- Moderate amounts of low-fat dairy foods and lean meats
- Small amounts of foods high in fat, sugar and salt
- Lean meat, chicken and fish (make sure it is low in mercury)
- Dried beans and lentils
- Nuts and seeds
- Green leafy vegetables.
Folic acid (folate) and pregnancy
Folate (known as folic acid when added to foods) is a B-group vitamin found in a variety of foods. Folate requirements increase substantially in pregnancy so women should aim to consume at least 600mcg (micrograms) of folate from their normal daily diet.
As well as a healthy diet, it is recommended that women planning a pregnancy take an additional 400mcg of folic acid each day for a month before and three months after conception. This may be taken as a supplement or in the form of fortified foods (food to which folate has been added during production). Folate taken over this period can prevent up to seven out of 10 cases of neural tube defects.
All wheat flour used in bread making in Australia must now contain folic acid (with the exception of flour used in ‘organic’ bread). Three slices of fortified bread (100g) contains an average of 120mcg of folic acid. Breakfast cereals and fruit juices sold in Australia may also have folic acid added.
Excellent food sources of folate include: asparagus, bran flakes, broccoli, brussels sprouts, chickpeas, dried beans, lentils and spinach.
Iron and pregnancy
Pregnancy increases the need for iron in the diet. The developing foetus draws iron from the mother to last it through the first five or six months after birth so a woman has an increased need for iron during pregnancy.
Iron losses are reduced during pregnancy because the woman is no longer menstruating and so loses less iron from menstrual blood loss. It is useful to include foods that are good sources of iron in the diet every day such as red meat. It is also important to have foods that are good sources of vitamin C (like oranges) to help absorb the iron.
Iodine and pregnancy
Iodine is an important mineral needed for the production of thyroid hormone, which is important for growth and development. Inadequate iodine intake during pregnancy increases the risk of mental impairment and cretinism in the newborn baby.
Foods that are good sources of iodine include seafood and seaweed (including nori and kelp), eggs, meat and dairy products. Women who are pregnant should also use iodised table salt when cooking or adding salt to food.
Due to the re-emergence of iodine deficiency in Australia, iodised salt is now added to all commercially sold bread in Australia and New Zealand with the exception of organic and unleavened bread.
Multivitamin supplements and pregnancy
Multivitamin supplements may be recommended especially for the following groups of pregnant women:
- Teenagers who may have an inadequate food intake
- Substance misusers (of drugs, tobacco and alcohol)
- Obese pregnant women who are restricting their energy intake to prevent large weight gains.
There is no need for extra calcium during pregnancy
Until 2006, Australian dietary recommendations advised increased calcium intake during pregnancy and breastfeeding. This advice has since been revised. Although there is a large ‘shift’ of calcium to the baby during the third trimester of pregnancy (as it starts to develop and strengthen its bones), the mother’s increased capacity to absorb dietary calcium makes up for this loss without the need for extra intake.
Eating for two
There is no need to eat more food during pregnancy. It is recommended that for the first trimester, a woman’s energy intake should remain about the same as it was prior to the pregnancy. During the second and third trimesters, energy requirements should increase by about 600kJ a day. Increasing fruit intake to four serves each day (from the recommended two serves for non-pregnant women) will provide all the extra energy needed.
Nausea and vomiting during pregnancy
Nausea and vomiting, especially ‘morning sickness’, are common during pregnancy – particularly in the first trimester. Small carbohydrate snacks (a sandwich or fruit) every two to three hours may provide some relief.
The following suggestions may also help:
- Eat some dry bread, biscuits or cereal before getting up in the morning.
- Get up slowly, avoiding sudden movements.
- Drink liquids between rather than with meals to avoid bloating as this can trigger vomiting.
- Avoid large meals and greasy, highly spiced foods.
- Suck something sour like a lemon.
- Relax, and get into the fresh air as much as possible. Keep rooms well ventilated & odour-free.
- Slowly sip a fizzy drink when feeling nauseated
- Try food and drinks containing ginger as these sometimes relieve nausea.
- Heartburn and pregnancy
Heartburn is common in pregnancy because, as the baby grows, there is more pressure on the abdomen. Small, frequent meals may be better than large meals.
Try to avoid:
- Eating late at night
- Bending, lifting or lying down after meals
- Excessive consumption of tea or coffee.
You may also like to try sleeping with your bedhead raised a few inches. You can do this by putting a folded blanket or pillow under your mattress.
Alcohol during pregnancy
There is no known completely safe level of alcohol consumption for women who are pregnant. Consuming alcohol during pregnancy increases the risk of miscarriage, low birth weight, congenital deformities and effects on the baby’s intelligence.
- Consider not drinking at all
- You should never become intoxicated (drunk)
- If you choose to drink, should have less than seven standard drinks over a week and no more than two standard drinks on any one day (at least two hours apart)
Listeria infection and pregnancy
Listeria infection, or listeriosis, is an illness usually caused by eating food contaminated with bacteria known as Listeria monocytogenes. Healthy people may experience no symptoms from listeria infection at all, but the risks are substantial for pregnant women. The greatest danger is to the unborn baby, with increased risk of miscarriage, stillbirth or premature labour. A listeria infection is easily treated with antibiotics, but prevention is best.
Some foods are more prone to contamination with listeria than others. Exclude these foods from your diet if you are pregnant:
- Soft cheeses, such as brie, camembert and ricotta – these are safe if served cooked and hot
- Precooked or pre-prepared cold foods that will not be reheated – for example, pre-prepared salads, pate, quiches and delicatessen meats like ham and salami (canned varieties are safe)
- Raw seafood such as oysters and sashimi or smoked seafood such as salmon
- Unpasteurised foods
- Soft-serve icecream.
- The organism that causes listeria infection is destroyed by heat, so properly cooked foods are not a risk.
Salmonella and pregnancy
Salmonella is a cause of food poisoning that can trigger miscarriage. The most likely sources of salmonella are raw eggs and undercooked meat and poultry.
Good food hygiene
Good food hygiene is the best way to reduce the risk of salmonella and listeria infections. Suggestions include:
- Always wash your hands before and after preparing food.
- Keep your kitchen surfaces clean.
- Do not let uncooked food contaminate cooked food.
- Wash fruit, vegetables and salad before eating.
- Cook food thoroughly.
- Keep pets away from kitchen surfaces.
- Wear rubber gloves when handling cat litter trays or gardening.
- Store food at correct temperatures.
Mercury in fish
It is suggested that pregnant women eat 2-3 serves of fish every week for the good health of themselves and their developing baby. However, pregnant women or women intending to become pregnant within the next six months should be careful about which fish they eat. Some types of fish contain high levels of mercury, which can be harmful to the developing foetus.
Pregnant women should:
- Limit to one serve (150g) per fortnight – billfish (swordfish, broadbill and marlin) and shark (flake), with no other fish eaten in that fortnight.
- Limit to one serve (150g) per week – orange roughly (deep sea perch) or catfish, with no other fish eaten that week.
- Eat 2-3 serves per week – of any other fish or seafood (for example, salmon or tuna).
- Note: 150g is equivalent to approximately two frozen crumbed fish portions.
Women should not be worried if they’ve had the odd meal of fish with high levels of mercury. It is only a potential problem when that type of fish is eaten regularly, which causes a build-up of mercury in their bodies.