Healthy eating during pregnancy is essential for both the development and growth of the baby as well as maintaining the mother’s health throughout this time. The food a mother eats during pregnancy influences the physical and emotional health of her child during childhood, adolescence and adulthood.
Increased Requirements During Pregnancy
While the requirements for some key nutrients do increase to support a healthy pregnancy, a common misconception is that a woman needs to eat for two. In fact, the overall energy requirements during pregnancy only increase by around 1400kJ during the second trimester (this is roughly equivalent to a peanut butter sandwich), and around 1900kJ during the third trimester (a peanut butter sandwich and a banana).
During pregnancy the requirements for folate and iodine increase. Folate plays a vital role in normal cell growth and development and can reduce the risk of neural tube defects in the unborn baby. The development of the neural tube occurs within the first four to six weeks of gestation and therefore it is recommended that a prenatal vitamin is taken prior to conception and for at least the first three months of pregnancy. Iodine is an essential nutrient that is used by the body to produce thyroid hormones which are important for the healthy development of the nervous system. Choose a prenatal vitamin that contains both folate and iodine.
Requirements for protein and iron increase to support pregnancy. The protein requirement increases by 14g per day during the second and third trimesters so by including an additional snack like two boiled eggs or a serve of Greek yoghurt you will be able to reach this target. Similarly, iron requirements increase by 9mg per day. Try and include lean sources of meat, poultry and fish as well as plenty of green leafy vegetables to help meet this requirement.
Nutrition during pregnancy should be focused on the overall quality rather than the quantity of food, meaning that if you consume mostly wholefoods including lean meat, poultry and fish, wholegrain breads and cereals, reduced fat dairy or dairy alternatives and plenty of fruits and vegetables you will likely achieve your nutrient requirements.
Water requirements generally increase during pregnancy to support an increase in blood volume. Water is essential to absorb and deliver nutrients to the baby, it can help to reduce fatigue and headaches, reduce the risk of urinary tract infections, and alleviate constipation, swelling, heartburn and nausea. A general guide is to drink at least 8-10 cups each day.
Foods to Avoid
A woman’s immune system is lowered during pregnancy. This means she is at a higher risk of contracting food borne illness if she should come into contact with it. Infection with certain bacteria which include listeria, campylobacter and salmonella can be dangerous to the unborn baby. To reduce the risk of contracting one of these bugs, certain foods should be avoided or eaten with caution.
- All meats should be fully cooked through
- Processed meats like ham, salami or chicken should be avoided unless heated to at least 75 degrees Celsius
- Freshly cooked and hot seafood is safe to consume but cold or raw seafood should be avoided
- Eggs should be cooked hard before eating and raw eggs in cake batter etc. should be avoided
- Pate and meat spreads must be avoided
- Always choose milks, creams and yoghurts that have been pasteurised
- Soft cheeses like brie, feta and ricotta should be avoided unless heated above 75 degrees Celsius
- Pre-prepared or pre-packaged salads and sandwiches should be avoided; instead make your own at home and wash salad ingredients beforehand
- Choose whole fresh fruits and wash before consuming rather than buying pre-prepared or pre-cut fruits
- Raw sprouts should be avoided but can be consumed after lightly cooking
- Always make sure to heat any leftovers to over 60 degrees and eat within one day of cooking
Foods to Limit
There are some foods that are safe to be consumed during pregnancy in limited amounts due to risks associated with a higher intake. Fish that are high in mercury can affect the nervous system of the unborn baby and while pregnant women are encouraged to consume fish as it is a great source of protein, iron and omega 3 fats, there are some fish that should be limited due to their mercury content.
- Shark (flake), broadbill, marlin and swordfish – should be consumed no more than once per fortnight with no other fish in that period
- Orange roughy (sea perch) and catfish – no more than once per week with no other fish in that period
- Any other fish is safe to be consumed two to three times per week as part of a balanced diet
Caffeine does not need to be completely excluded, however because the unborn baby cannot process caffeine in the same way as an adult, food and drinks that contain caffeine should be limited to 200mg per day. Below is a guideline of how much caffeine is contained in some common foods and drinks.
- Espresso coffee (1 shot): 90mg
- Instant coffee (1 tsp): 80mg
- Black Tea (1 bag): 48mg
- Green Tea (1 bag): 32mg
- Coca-Cola (600ml): 60mg
- Chocolate (50g bar): 10mg
During pregnancy a woman’s body is experiencing rapid changes and a surge of hormones. A number of hormones likely contribute to nausea and vomiting during the first trimester of pregnancy including hCG, oestrogen and progesterone. A pregnant woman may also experience food cravings, food aversions, heartburn and constipation. While most of these symptoms occur during the first 12 weeks of pregnancy, for some they may continue throughout the pregnancy or come and go dependant on the individual.
If a woman experiences nausea or food aversions during her pregnancy she may struggle to consume nutritious foods during certain times of the day. She should aim to include foods that are nutritious and healthy during the times of day she feels at her best. For example, if mornings are the time when she feels most unwell, try and include plenty of fresh and nutrient dense foods as part of a late lunch or dinner. Some strategies that may help to relieve or manage morning sickness include snacking on plain dry foods like wholegrain crackers, including ginger in meals or in ginger tea and avoiding foods with strong smells or while foods are cooking.
Heartburn during pregnancy can occur because the hormones released during pregnancy may relax the stomach and oesophagus and allow stomach acids to move upwards. To reduce the effects of heartburn, take note of which foods you’ve eaten that may have caused your heartburn and avoid them. Foods that commonly trigger heartburn include garlic, onion, tomatoes, caffeinated food or drink, citrus fruits and fatty and spicy foods. You may also find it helpful to avoid large meals and instead eat smaller and more frequent meals to allow your body to digest and absorb them more efficiently, eating slowly and chewing food well and avoiding laying down after eating.
Constipation is common throughout pregnancy due to the intestinal muscles becoming relaxed, the pressure of an expanding uterus on the intestines as well as inadequate fibre and water intake. If a woman is taking iron supplements this may also contribute to constipation. To prevent or alleviate constipation a pregnant woman should eat a diet high fibre to increase bulk as well as soften the stool making it easier to pass. Including lots of fruits, vegetables and wholegrains in her diet will ensure she is consuming plenty of fibre. Drinking plenty of fluids is essential to assist the fibre in removing waste. Regular exercise or physical activity may also help to stimulate the bowels. Aim for 30 minutes of light to moderate exercise each day.
Take home message
When it comes to nutrition during pregnancy a woman should aim to eat a balanced diet full of fresh and whole foods from the five food groups to meet her increased nutritional requirements and support the growth and development of her baby. However, some foods carry a higher risk for food borne illness so should be avoided during pregnancy. The nutrition that the baby receives prior to birth can influence their health into childhood and beyond making it important to lay a strong foundation prior to and during pregnancy. The nutritional requirements of women during pregnancy vary between individuals and can be a complex field to navigate. So, if you are pregnant and need advice tailored to your personalised needs, it is a good idea to seek the advice of an APD.
Accredited Practising Dietitian