Dr Jacqueline E Campbell
MANY pregnant women become concerned about what they should and shouldn't be eating. That is understandable as a healthy diet contributes to a successful pregnancy by reducing complications and promoting adequate foetal growth and development. Nutrition is thus an essential component of prenatal care.
A well-balanced diet contributes to normal birth weight for the baby, improved foetal brain development, decreased chance of pregnancy complications such as morning sickness, fatigue, mood swings, anaemia and pre-eclampsia (life-threatening condition that often occurs in the 3rd trimester - symptoms include high blood pressure, protein in urine, edema, blurred vision, pain around the liver) and a speedy recovery after delivery.
Weight gainWeight gain is desirable for all women since it is essential for normal foetal growth. It is important not to restrict calories during this time. Generally a pregnant woman should aim to keep her weight gain around 20 to 30 pounds. The recommended increase in weight gain does not give a green light for mothers-to-be to overeat as excessive calorie intake will lead to excess weight gain - a situation that must be avoided. Although extra nutrients are required, an increase of only 300 calories per day is recommended.
What to eatEven before pregnancy begins, nutrition is a primary factor in the health of mother and baby. A well-balanced diet before conception contributes to a healthy pregnancy and will probably need few changes when pregnancy occurs. The basis of a well-balanced diet is a balance of grains, fruits and vegetables, protein, dairy and fats. A balanced diet should be built around the five big nutrients of pregnancy - calcium, complex carbohydrates, good fats, iron and protein.
According to the American College of Obstetricians and Gynaecologists, pregnant women should increase their usual servings of a variety of foods to include a total of four or more servings of fruits and vegetables, four or more servings of whole-grain or enriched bread and cereal, four or more servings of milk and milk products, and three or more servings of protein - meat, poultry, fish, eggs, nuts, and dried beans and peas.
Grain products are the main source of complex carbohydrates. Complex carbohydrates provide energy, prevents constipation and nausea, and gives essential nutrients including fibre, folate, Vitamin B and protein. They can be obtained by eating whole grains such as whole-wheat bread, cereals, brown rice or pasta. Refined grain products such as white bread and white rice, biscuits and cakes should be avoided as these are of little nutrient value.
Fruits and vegetables will provide essential vitamins and minerals as well as fibre to aid digestion and prevent constipation. Vitamin A derived from green leafy vegetables and yellow fruits is important for the development of the baby's bones, skin, hair and eyes. Vitamin C is important for bone growth and tissue repair.
Protein is composed of amino acids, the building blocks of human cells which are crucial for a developing foetus. It is also important in protecting against the development of pre-eclampsia later in pregnancy. Protein foods are also normally iron-rich foods, important to keep the blood well-oxygenated.Dairy: Getting enough calcium can help prevent a new mother from losing her own bone density as the foetus uses the mineral for bone growth.
Calcium is also needed for the development of teeth, muscle, heart, nerves and blood.Fat: Some fats are necessary for the baby's development, but these should be limited to manage weight gain during pregnancy. An occasional sweet treat is fine, but should not be included as a daily part of the diet. Essential fats are found in polyunsaturated oils such as sunflower and soya bean oils, and monounsaturated oils such as olive and canola oils.
Water and fluids: The body's need for fluids will increase as the pregnancy progresses. An adequate fluid intake will help in the prevention of early labour, stretch marks, and constipation. Caffeine-containing beverages such as coffee, tea and colas should be limited to only one cup per day.
What not to eatIn addition to foods a pregnant woman should consume, there are also foods that should be avoided. One of the big concerns for pregnant women is the risk of eating harmful bacteria - listeria and salmonella - which can lead to miscarriage, early labour and toxemia.Listeria
The bacteria Listeria monocytogenes is often present in certain foods, and in low levels may have no effect on healthy people and often goes unnoticed. However, if ingested by a pregnant woman, it can lead to miscarriage, stillbirth or early labour. Foods at higher risk of containing listeria include cold foods that will not be reheated, including pate, deli meats like ham and salami, and pre-mixed salads; soft serve ice cream; soft cheeses, such as brie, ricotta; smoked seafood and any leftovers kept in the fridge for more than 12 hours.
SalmonellaThis is a form of food poisoning that can trigger miscarriage or premature birth, and is most often traced to undercooked poultry and meats, and raw eggs. Other foods to avoid include raw meat and seafood, including sushi, sashimi and hot dogs.
ToxoplasmosisUndercooked meat can be contaminated with a parasite that causes toxoplasmosis. If a pregnant woman becomes infected, the infection can be transferred to the foetus - potentially resulting in a miscarriage.Other food considerations
Fish: Pregnant women, nursing mothers, and women of childbearing age who may become pregnant should be aware of the hazards of eating certain kinds of fish, specifically shark, swordfish, king mackerel, and tilefish, because these fish may contain high levels of methyl mercury which may harm an unborn baby's developing nervous system.
Nuts: If there is a family history of food allergies, it is best to avoid eating peanuts or products containing peanuts. Peanut allergy is a serious health concern that is on the increase. Exposure to peanuts during pregnancy and through breastfeeding can increase the chance of the allergy developing if the baby has a predisposition.
Vitamin A: Although vitamin A is essential during pregnancy, supplements and foods particularly high in Vitamin A are not recommended, because of the risk of birth defects.
Alcohol: No safe level of alcohol has been established for pregnant women. Because of this, abstinence is the safest choice. The issue of drinking alcohol during pregnancy is somewhat controversial. Some practitioners believe that an occasional dilute drink, or a small glass of beer or wine once or twice a week is harmless. Others feel that current research indicates even as few as one to two drinks per week may cause harm to the foetus by increasing risk of prematurity or low birth weight. Excessive intake is definitely associated with a condition called Foetal Alcohol Syndrome, which can cause permanent mental retardation and congenital deformities.Intake of alcohol should be avoided even while trying to conceive.
Cigarette smokingCigarette smoking during pregnancy is associated with low maternal weight gain and low birth weight of the baby. Children of mothers who smoke are also at greater risk for certain diseases and may have learning problems.
What about supplements?Although taking supplements will not replace eating a nutritionally potent array of foods, supplement will ensure that the right balance of nutrients is taken. In fact, women who are only thinking about getting pregnant should begin taking prenatal supplements. Also as soon pregnancy is confirmed, a prenatal vitamin should be taken. Supplementation during pregnancy is very important.
Research has shown that supplementing with 400 mcg of folic acid every day beginning 12 weeks before conception guards against neural tube defects. Other important supplements are:. Calcium - 1,500mg per day. Omega 3 fatty acids - 1,000mg per day. Choline 450 to 1000 mg per day. Vitamin D 400 IU per day
Supplementation with anti-oxidants is also important as pregnant women with pre-eclampsia have abnormal anti-oxidant defences and supplementing with Vitamin C and E daily, in addition to taking a prenatal vitamin, may help reduce the chances of pre-eclampsia in high-risk women. Although further research is needed, studies have shown that women with pre-eclampsia have higher levels of homocysteine and lower levels of folic acid.
Supplementing with extra folic acid can help keep homocysteine levels within normal range. In addition to preventing neural tube defects, good dietary choices may prevent certain diseases such as acute lymphoblastic leukemia, liver disease, diabetes and pre-eclampsia.Dr Jacqueline E Campbell is a family physician in private practice.