Pregnancy and diet

Good nutrition during pregnancy helps keep you and your developing baby healthy. Pregnancy increases your need for certain nutrients — especially iron, iodine and folate — but it is better to focus on the quality of your diet than simply on eating more. A dietitian can review whether you need any supplements.

Healthy weight gain during pregnancy#

Steady weight gain during pregnancy is normal and important for you and your baby. It is also important not to gain too much, as excess weight can make it harder to lose afterwards and can raise the risk of problems such as gestational diabetes.

The right amount of weight gain depends on your body mass index (BMI) at the start of pregnancy, so ask your midwife, doctor, dietitian or obstetrician what range is suitable for you and to help you monitor your weight. A good approach is to eat to satisfy your appetite, choose healthy foods, and stay active. If you are overweight, pregnancy is not the time to start dieting or trying to lose weight, because gaining within the recommended range supports your baby’s growth and development.

To support an appropriate weight gain:

• Choose healthy foods from the main food groups.
• Limit foods and drinks high in saturated fat, added sugar and added salt, such as cakes, biscuits and sugary drinks.

Healthy eating for pregnant women#

What you eat during pregnancy affects your own health and your baby’s development, and there is good evidence it can have a lasting impact on your child’s health later in life. Choose a wide variety of healthy foods so that both your nutritional needs are met. You may need more of some foods to get enough key nutrients, but there is no need to “eat for two.”

General daily guidance during pregnancy includes:

• A variety of fruits and vegetables of different types and colours — around 2 serves of fruit and 5 serves of vegetables each day.
• Plenty of grain and cereal foods (around 8 to 9 serves a day), mostly wholegrain and high-fibre.
• Around 3½ serves of lean meat, poultry, fish, eggs, tofu, nuts, seeds or legumes — iron-rich foods are especially important.
• Milk, yoghurt and hard cheese, or calcium-enriched alternatives, mostly reduced-fat varieties.
• Plenty of water.

Limit foods and drinks high in saturated fat, added sugar and salt. When using canned foods, choose those with no added salt.

Folic acid (folate)#

Folate (called folic acid when added to foods) is a B-group vitamin. It helps protect against neural tube defects in the developing baby. For women planning a pregnancy and during the first three months of pregnancy, a daily folic acid supplement of 500 micrograms is commonly recommended, along with eating foods naturally rich in folate or fortified with folic acid.

Good food sources of folate include asparagus, broccoli, Brussels sprouts, spinach, cabbage, cauliflower, leeks, peas, chickpeas, dried beans, lentils, oranges and orange juice, wholegrain bread, bran flakes, wheat germ, nuts, strawberries and tomato. Liver is high in folate but is not recommended in pregnancy because of its high vitamin A content.

Iron#

During pregnancy a woman’s need for iron rises, because the developing baby draws iron from the mother to last through the first five or six months after birth. Although iron losses fall during pregnancy because menstruation stops, this is not enough to meet the baby’s needs.

Eat iron-rich foods every day, such as meat, chicken, seafood, dried beans, lentils, and green leafy vegetables. Iron from animal sources is absorbed readily. Iron from plant sources is absorbed less easily, but eating it with foods containing vitamin C (such as oranges) helps absorption — this is especially important for those following a vegetarian diet.

A common recommended daily intake of iron during pregnancy is 27 mg a day (about 9 mg more than for non-pregnant women). Iron deficiency in pregnancy is common, and some women may need supplements. Discuss any supplements with your doctor, as iron can be toxic in large amounts.

Iodine#

Iodine is needed to make thyroid hormone, which is essential for growth and development. Too little iodine in pregnancy increases the baby’s risk of mental impairment and congenital hypothyroidism (previously known as cretinism).

Good sources of iodine include seafood, seaweed (such as nori and kelp), eggs, meat and dairy products. Iodized salt also provides iodine. It is best to limit added salt, but if you use it, choose iodized salt. Pregnant and breastfeeding women have higher iodine needs, and a supplement of 150 micrograms a day is commonly recommended for women planning a pregnancy, throughout pregnancy and while breastfeeding.

Vitamin D#

Vitamin D is important for bone health and for healthy pregnancy outcomes. Most vitamin D is made in the skin from sunlight; only a small amount comes from foods such as eggs, oily fish, and milk or margarine fortified with vitamin D.

Women at greater risk of vitamin D deficiency include those who spend a lot of time indoors, have dark-coloured skin, or wear covering clothing. Vitamin D can also be harder to get in winter. You may need a blood test to check your levels, and depending on the result your doctor may recommend a supplement. It is not beneficial to take vitamin D supplements if you do not need them, so always discuss it with your doctor first.

Calcium#

Although the baby has a high calcium requirement in the third trimester as it builds its bones, the mother’s increased ability to absorb dietary calcium means there is usually no need for extra intake. Older advice once recommended increased calcium in pregnancy, but this has since been revised. The recommended intake for non-pregnant women (about 1,000 mg a day for women aged 19 to 50, and 1,300 mg a day for adolescents or those over 51) stays the same during pregnancy and breastfeeding.

Dairy foods such as milk, cheese and yoghurt, and calcium-fortified soy milk, are excellent sources.

Multivitamin supplements#

A varied diet from the main food groups usually provides the vitamins and minerals you need. However, supplements (such as folate and vitamin D) may be recommended for some groups, including vegans and vegetarians, teenagers with an inadequate food intake, and those who misuse drugs, tobacco or alcohol. Always consult your doctor before taking any supplements, as they may recommend a blood test first.

Dieting and pregnancy#

Some women fear weight gain and eat sparingly to avoid putting on body fat. Restricted eating or crash dieting in any form while pregnant can seriously harm your health and your baby’s, and is not recommended.

Pregnancy in adolescence#

Pregnant adolescents need more of some nutrients than adult women because they are still growing themselves, and they may give birth to smaller babies as they compete with the baby for nutrients. Getting enough iron is important. Calcium also matters, because young women have not yet reached their peak bone mass and inadequate calcium may raise the risk of osteoporosis later in life. Pregnant adolescents should aim for around 3½ serves of milk, yoghurt, cheese or calcium-fortified alternatives each day.

Common digestive complaints#

Constipation is common in pregnancy. To help, eat plenty of high-fibre foods such as vegetables, legumes, fruit and wholegrains, drink plenty of water, and stay physically active.

Nausea and vomiting, especially “morning sickness,” are common in the first trimester. Suggestions that may 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.
• Avoid large meals and greasy, highly spiced foods.
• Suck on something sour, such as a lemon.
• Rest, relax and get fresh air; keep rooms well-ventilated and free of odours.
• Try ginger-based foods and drinks, such as ginger tea.

Heartburn is common as the growing baby presses on the abdomen. Small, frequent meals may help more than large ones. Try to avoid excessive tea or coffee and eating late at night, and avoid bending, lifting or lying down after meals. Raising the head of your bed slightly, for example by placing a folded blanket under the mattress, may also help.

Alcohol during pregnancy#

There is no known safe level of alcohol consumption during pregnancy. Drinking alcohol increases the risk of miscarriage and other harm, so not drinking is the safest option. If you find it difficult to cut down or stop, talk to your doctor or midwife, or a local alcohol and other drug service.

Food safety in pregnancy#

Listeria#

Listeria infection (listeriosis) is caused by Listeria monocytogenes. Healthy people may have no symptoms, but the risks are serious in pregnancy, with the greatest danger to the unborn baby — including miscarriage, stillbirth or premature labour. Listeria is easily treated with antibiotics, but prevention is best. The organism is destroyed by heat, so properly cooked foods are not a risk. Avoid foods more prone to contamination, such as:

• Pre-cooked or pre-prepared cold foods that will not be reheated, such as pre-prepared salads, pâté, quiches and delicatessen meats like ham and salami.
• Soft cheeses, such as brie, camembert and ricotta (safe if served cooked and hot).
• Raw or smoked seafood, such as oysters, sashimi or smoked salmon (canned varieties are safe).
• Soft-serve ice cream and pre-packaged cut fruit and vegetables.

Salmonella#

Salmonella is a cause of food poisoning that can trigger miscarriage. The most likely sources are raw eggs and undercooked meat and poultry.

Good food hygiene#

Good hygiene is the best way to reduce the risk of salmonella and listeria infections:

• Always wash your hands before and after preparing food.
• Keep kitchen surfaces clean and store food at correct temperatures.
• Do not let uncooked food contaminate cooked food.
• Wash fruit, vegetables and salad before eating.
• Cook food thoroughly.
• Keep pets away from kitchen surfaces, and wear gloves when handling cat litter trays or gardening.

Mercury in fish#

Eating fish 2 to 3 serves a week is good for you and your baby. However, some fish contain high levels of mercury, which can harm the developing baby. If you are pregnant or may become pregnant within the next six months, limit high-mercury fish:

• Limit billfish (swordfish, broadbill and marlin) and shark (flake) to one serve (about 150 g) per fortnight, with no other fish that fortnight; or
• Limit orange roughy (deep sea perch) or catfish to one serve (about 150 g) per week, with no other fish that week; or
• Eat 2 to 3 serves per week of other fish or seafood, such as salmon or tuna.

A serve of about 150 g is roughly two crumbed fish portions. Do not worry about the occasional high-mercury meal — mercury build-up is only a concern when such fish is eaten regularly.

Key points#

• Steady weight gain during pregnancy is normal and important for you and your baby.
• It is also important not to gain too much weight.
• Gaining within the recommended range supports your baby’s growth and development.
• Iron-rich foods are important during pregnancy.
• It is important to make sure you are getting enough folate.

Where to get help#