Eating healthily during pregnancy helps the growth and development of the developing foetus as well as the mother’s wellbeing. Not only do pregnant women need to eat well, but they need to eat carefully (avoiding unsafe foods) and eat more as baby grows (not a substantial amount, but some).
Pregnancy and breastfeeding are nutritionally very taxing. The body of a pregnant woman is making extra demands due to an increase in blood volume, cardiac output and changes in breast tissue to prepare for breastfeeding, hormonal changes, growth of the placenta and changes in a number of major organs. It is vital that a pregnant woman eats well, ensuring not only her good health but that of her developing baby.
In addition, gastric functioning slows, delaying gastric emptying, and along with the slowed intestinal processing this increases the absorption of nutrients from food. Keep in mind though that this can contribute to constipation as more water is absorbed from the colon.
Pregnancy and body changes
During pregnancy, the blood volume may increase by as much as 50%. Red blood cell mass, however, may increase by only 20%, consequently there is a fall in haemoglobin and the concentration of nutrients in the blood. Hence blood results cannot be compared to non-pregnant women, but unfortunately there is only limited data with which to interpret blood nutrient levels at present.
Weight gain and pregnancy
There are no recommendations for weight gain during the first trimester, though on average most women gain 1–2kg in total. Over the second and third trimesters, an average gain of 0.4 kg/wk is expected, with a total average gain of 10-13 kg for women in the normal body mass index (BMI). US data recommends for the best foetal and delivery outcomes women whose BMI is less than 19.8 gain 12.5–18kg and women in the high BMI (26-29), 7–11.5kg, while those with a BMI exceeding 29 should gain around 7kg, though the data on this is very sketchy to date.
The composition of weight gain
44% fat stores and fluid retention
The remainder spread between placenta, increased blood volume, increased
maternal tissue and amniotic fluid
While there is enormous variation over fat mass deposition during pregnancy, influenced by pre-pregnancy weight, energy intake and energy expenditure, the majority of fat is deposited around the abdomen, back and upper thighs. The deposition tends to occur early in the pregnancy and, importantly, acts as a form of fuel for the mother in order to spare glucose for the foetus. Some remaining stores are used during lactation.
Underweight women are more likely to give birth to small-for-gestation-age infants (GAI), which may increase the risk of respiratory and gastrointestinal issues in the infant and increase the mortality rate. Women who are underweight are advised to eat a further 150 kJ per day than women of normal weight.
Most developed countries are experiencing an increase in gestational diabetes (five- time increase in the EU in four years) and an increase in large-for-gestational-age (greater than 4kg) babies. The Australian Institute of Health and Welfare has documented a six-time increase in gestational diabetes and the use of insulin over the period from 2000 to 2007. Obesity in pregnancy has been shown to be associated with increased gestational diabetes, hypertension, caesarean, post-operative complications, neural tube defects (NTDs) and large-for-gestational-age babies (LGA). While weight loss during pregnancy is not recommended, weight gain is expected to be less than under normal situations.
Two factors to date have been highlighted; food volume and decreased physical activity. Women reporting a significant increase in their food volume during pregnancy are more likely to gain excessive weight. Likewise, women who reduced their physical activity also experienced more weight gain in pregnancy.
General nutritional recommendations
Eating while pregnant is not that different from general healthy eating practices: the diet should be sensible, clean, varied and healthy. Keep in mind that, as the pregnancy progresses, activity generally decreases, so some of the increased energy needs can be offset naturally. More specifically though, while pregnant, be sure to include the following:
Ample fruit and vegetables
Lots of wholegrain breads and cereals (food is best if it resembles its original state,
i.e. same colour)
Include lean meat, chicken and fish regularly and some protein in each main meal
If vegetarian, ensure protein-combining principles and have at least two or more protein sources at each meal to get all the essential amino acids.
Try to include some vegetarian meals each week (following protein-combining principles)
Look for healthy fats such as those from nuts, seeds and fish and keep the unhealthy fats under control (pastries, processed meats and so on). Enjoy a small handful of nuts and seeds each day
Ensure intake of healthy calcium-containing foods from dairy, tinned fish and calcium-fortified drinks
Limit sugar intake by cutting-down on foods with added sugar and by reducing the sugar added to meals and baking
The same goes for salt
A special note on teenage pregnancy
Adolescence is a period of dramatic growth and development in any young woman’s life. Additional nutrients will be required by pregnant teens for support. Unlike pregnant post-adolescent women, pregnant teens and their baby may compete for the nutrients in their diet as both are growing. Adolescent mums-to-be should consider this when planning meals; make sure they are eating enough to meet their own growing needs as well as their baby’s. Eating well will help them avoid undue stress and reduce the chances of their child being born prematurely or underweight.
Is there anything that should be avoided?
Indeed, some foods should be avoided, such as certain cheeses, fish and even meat. In general, it is best to avoid a restrictive diet while pregnant or breastfeeding as it can affect the health and wellbeing of both mother and baby. Nutrient deficiencies will impact on a developing baby, and they can also affect the mother’s state of mind and overall health. Pregnant women should follow a good healthy diet and stay active (in relation to their stage of pregnancy).
Listeria moncytogenes infection can cause a mild state of being unwell during pregnancy; however, it can lead to miscarriage, stillbirth, premature birth or issues with the foetus. High-risk foods include:
Smoked fish, including mussels, oysters and raw fish
Pre-prepared salad, including coleslaw due to the mayonnaise
Pre-cooked meat products that do not require further cooking, such as pâté and deli meats
Unpasteurised milk and products made from it
Soft cheeses, largely due to surface moulds
What foods are best avoided in pregnancy?
Avoid chilled or uncooked seafood products, which can often carry bacteria harmful to your bub.
The same applies to other chilled, precooked meat products such as chicken or ham, as well as stored salads and unpasteurised milk.
Try to avoid foreign cheeses which use unpasteurised milk.
Raw/rare beef and poultry should also be avoided because of the risk of
exposure to potentially harmful bacteria such as Salmonella.
Avoid raw eggs or food containing raw egg (homemade mayonnaise) to
reduce the risk of Salmonella poisoning
Excessive liver intake can increase your risk of vitamin A toxicity. Unfortunately,
the same applies for pâté on the cheese platter.
All fresh foods should be washed thoroughly before eating.
Alcohol consumption at any level is unsafe, hence it should be avoided.
Limit or avoid caffeinated beverages such as tea and coffee (especially in the first trimester where miscarriage is more common). If a coffee fix is essential, limit it to one cup a day (heavy intake has been shown to affect a baby’s growth and development).
Keep an eye on drinks high in sodium, such as many sports drinks.
Keeping well hydrated is also important, so try to avoid tea and excessive green tea (which has even more tannin) where possible and ensure you drink plenty of water.
Foods high in sugar (fizzy drinks or undiluted fruit juices), unhealthy fats (French fries, cakes or chocolate) and salt (potato chips or pre-packaged noodles or stock) should all be eaten in moderation, i.e. have them as treats.
Fish high in mercury such as shark, swordfish, king mackerel, fresh tuna, sea bass and some fish found in sushi should be eaten in moderation to avoid developmental delay and brain damage associated with mercury poisoning.
Australia and New Zealand are generally thought of as safe fishing areas. However, consider the origin of seafood that you buy, as many regions such as parts of Asia may have issues with water quality.
Fish oil is commonly known to be beneficial in pregnancy; however, more is not necessarily better. Always be guided by directions on labels or from your health care professional.
What about the odd tipple?
There is clear evidence that consuming alcohol during pregnancy can affect foetal development as it’s linked to low birth weight, miscarriage, and other serious concerns. Recently, most agencies have updated their recommendations to suggest the avoidance of alcohol during pregnancy.
Additional intake Protein
RDI (Recommended Daily Intake) +14 mg per day from the second trimester onwards, however, data on this is still very sketchy to date.
Folic acid (folate)
Folate is a B-group vitamin found in a variety of foods. Folate (B9) reduces the chances of baby developing brain and/or spinal cord defects, and is therefore essential not only in a pregnant woman’s diet but in the diet of any woman of child- bearing age (15-45). This vitamin is required for the normal development of the nervous system, particularly the closure of the neural tube, which occurs during the first six weeks of pregnancy. Interestingly, it appears that it is not a deficiency concern, but rather that some women have an inability to process folate and the supplementation bolsters supply to overcome this.
Women may not know that they are pregnant for up to four weeks, so ensuring adequate nutrient intake of folate around the time of conception is also important. For this reason, the National Health and Medical Research Council (NHMRC) recommends that all women planning a pregnancy should take at least 400mcg of folate daily for one month prior to planned conception (women at higher risk may be advised to take more). Supplementation should continue throughout the first trimester. If the neural tube fails to properly close, birth defects such as spina bifida can occur – these defects affect one in five hundred pregnancies in Australia.
When folate is added to food it is known as folic acid, and many labelled products are now fortified with B9. Many of our breakfast cereals, breads and juices are fortified with folic acid.
As well as including folate in their diet, supplementation is generally recommended given the huge drop in NTDs with folic acid intake.
What about iron?
Despite not having a menstrual cycle while pregnant, iron is required for maternal and foetal haemoglobin production, with the foetus storing most of its iron in the last trimester, which will be a store of iron for the first six months of the infant’s life.
Anaemia during delivery can potentially create an issue for oxygen supply to the infant, and anaemic mothers can be less able to cope with obstetric complications.
Foods such as red meat, liver, kidney, broccoli, peas, bran, oats and enriched breads are great sources of iron and should be incorporated into your daily diet. Alternatively, vegetarians can obtain some iron through tofu, pumpkin seeds, peaches, sesame seeds or tahini.
Keep in mind that vitamin C assists in the absorption of iron, so enjoy vitamin C-rich foods such as guava, red capsicums, blackcurrants, strawberries, oranges, watercress, cabbage (savoy), Brussels sprouts, kiwi fruit, paw paw, broccoli, cooked tomatoes and cauliflower.
It is general practice that a mother will have her iron levels checked twice during pregnancy. While iron is commonly low in pregnant women, it’s also important to understand how much is needed in order to keep iron within a healthy range. More is not better. Check with your healthcare professional for the recommended dosage.
The RDI for iron in pregnancy is 27mg/d; this is increased by 1.8 times for vegetarian mothers. While there is ongoing debate as to whether a diet can provide such amounts of iron, it appears there is some compensatory mechanism that increases the absorption of iron from the diet during pregnancy. However, consumption of iron- fortified foods is recommended.
Keep in mind that iron absorption differs in relation to the type of iron, the nutrients in the food with which it is eaten (vitamin C increases the absorption and calcium lowers it) and so on.
Supplementation is commonly recommended for women at risk of iron-deficiency anaemia (IDA), such as those:
Following a vegetarian or vegan diet
With repeated pregnancies
Who have a history of anaemia or entering into pregnancy already low in iron.
Women who experienced IDA during pregnancy or are from an indigenous background are more likely to have infants with IDA.
Studies in around the world have highlighted that iodine deficiency is becoming increasingly common in pregnant women and young children. Iodine is important for normal growth and development, metabolism and brain function. Pregnant women require more iodine because their pool of iodine must meet their needs and the needs of their fast-growing baby. Many countries are turning to iodine fortification of food. Using iodised salt is a good way to increase your intake, in October 2009 all commercial breads made in Australia and New Zealand began using iodised salt (excluding organic bread). However, if there is concern about salt intake, there are a number of very good pregnancy supplements and most now include iodine.
With growing global concern over iodine and iodine deficiency disorders (IDD), WHO has rated the level of deficiency classification as follows:
< 20 μg/L, severe
20 – 49 μg/L, moderate
50 – 99 μg/L, μg/L, mild
≥ 100 μg/L, iodine-replete status
Iodine deficiency issues in pregnancy and childhood
Iodine is required by the thyroid gland to synthesise iodine-containing thyroid hormones that among other functions, are involved in:
Growth hormone secretion
Central nervous system (CNS) development
Synthesis of many enzymes (Medical Journal of Australia, 1999)
Pregnant women are more at risk of iodine deficiency as there is a greater requirement during pregnancy to ensure normal metabolism and provide sufficient transfer of iodine to the rapidly developing foetus (Travers et al, 2006). The spectrum of iodine deficiency disorders (IDD) is very wide; in relation to pregnancy and childhood, however, they include perinatal mortality, congenital abnormalities, stillbirth, goitre, deaf mutism, mental retardation and premature birth (McDonnell et al, 2003).
Even mild deficiency can result in IDD. Iodine deficiency in critical periods of human development, (either as a consequence of reduced dietary intake or reduced maternal supply), for example deficiency during foetal neuronal development, or the third month of life, can result in irreversible neurological impairment of an infant. WHO suggests that iodine deficiency is the ‘greatest cause of preventable brain damage in childhood...’ (WHO pp ,7).
Any nutrient that has the potential to affect birth outcomes, growth and neurological development – even at a mild deficiency level (McDonnell et al, 2003) – is likely to have generational implications to any population; hence potential iodine deficiency is a major health concern.
Not too much vitamin A
Excessive vitamin A intake can be detrimental to the development of the foetus, hence it is recommended to avoid taking supplements unless approved by a healthcare professional. Vitamin A requirements do not change during pregnancy, but it may be wise to keep an eye on how much vitamin A-rich food is consumed.
The latest guidelines now suggest that even though there is a ‘shift’ of calcium from mother to foetus – who is laying down bone structure during the third trimester – it seems the woman’s body copes by improving its ability to absorb calcium from the diet. Increased calcium absorption from the gut (of about 30-40%) and decreased urinary excretion appear to be the primary mechanisms for the balance.
WHO guidelines recommend an increase in intake of calcium by 1.5-2g per day where dietary calcium is low or where women are known to be at risk of developing issues such as preeclampsia (2004).
So, the recommended dietary intake for non-pregnant women (1,000mg per day for women aged 19–50 years and 1,300mg per day for adolescents) remains unchanged during pregnancy and breastfeeding.
Dairy foods such as milk, cheese and yoghurt, calcium-fortified soymilk and tinned fish with bones are excellent dietary sources of calcium. While there appears to be some bone mobilisation in the latter stages of pregnancy, studies suggest that pregnancy does not have a negative impact on bone mineralisation (Paton et al, 2003); potentially there may be an increased re-deposition after delivery.
It is always advisable to seek professional advice if considering taking a supplement during pregnancy and breastfeeding. In some cases, vitamins and minerals can mask deficiencies or even interact with medications.
If you are not qualified, your healthcare professional might recommend a multivitamin supplement if you fit into the following categories:
Teenagers who may have an inadequate food intake
Women with an inadequate diet or under stress or those who smoke or are exposed to other chemicals, either by trade or geography
Substance misusers (of drugs, tobacco and alcohol)
Obese pregnant women who are restricting their energy intake to prevent large weight gains.
Common issues in pregnancy
Tips to cope with nausea and vomiting during pregnancy
Most expectant mothers experience only mild morning sickness, yet for some mothers- to-be this is not the case. So, while of course some of these tips may help, in honesty sometimes nothing short of intervention (for example by medication) can relieve extreme morning sickness.
Some suggest that it is the hormonal changes and increased hormonal activity that place a burden on the detoxifying functions of the liver, leading to an ‘overflow’ that causes morning sickness. Although this certainly makes perfect sense, it’s a little bewildering because even a clean-living person who rarely drinks or eats junk and doesn’t smoke can suffer with morning sickness. Medically, it is still considered unclear. Some practitioners believe it is a blood sugar issue, hence the advice to eat before rising and to consume low-GI foods.
So, here are some tips:
Eat a protein-containing snack before retiring at night, for example, a smoothie
with yoghurt and fruit.
Eat a dry cracker or toast before rising from bed and get up slowly.
Stay well-hydrated, but drink in between meals rather than with food to avoid bloating.
Eat small but very regular meals (this will also be helpful when bub starts to encroach on the abdominal space).
Try sea-sickness wrist bands (available from chemists).
Acupuncture works well for some.
There are some nutritional supplements made for morning sickness that have B6,
ginger and other elements.
Ginger is commonly used for nausea and seasickness, so can be trialled as a tea made with freshly grated ginger or a pinch of ginger powder; you might also add it to cooking.
Eat ginger biscuits.
Drink flat ginger ale.
Watch out for fatty and spicy foods as they can further upset an already upset tummy.
Relaxation techniques may help.
Slowly sipping on a fizzy drink has been helpful for some.
Some woman may find as they progress through pregnancy and space is at a premium that heartburn becomes an issue. Try to:
Avoid too much tea and coffee (or, at the very least, opt for naturally
Not eat late at night
Avoid too much bending, lifting or lying down after eating. Try to stay partially
upright to allow the passage of food to move down with the assistance of gravity.
Talk to a healthcare professional, for example a naturopath, about some digestive enzymes such as plant-based enzymes or other nutritional supplements that aid digestion.
Reducing allergy in the family
In the past, avoiding allergy-causing foods was thought to be a good way to reduce the risk of your child being allergic. To date there is no evidence to support the theory that altering your diet whilst pregnant will reduce this risk. Expectant mothers should strive to ensure a diet full of variety!
Some pregnant women may need to make special adjustments to their diet and should consider seeking nutritional advice from a suitably qualified health care professional. You may need to take special considerations if you;
Are very young (adolescents who are still growing)
Are underweight or overweight at the time of becoming pregnant
Have had more than three pregnancies in two years
Eat a restricted diet (e.g. macrobiotic, vegan)
Have been eating a diet that you consider has been unhealthy and may compromise you nutritional status
Have any complications related to your general health and/or pregnancy.