Studies revealed that less than 50% of pregnant women meet the recommendations for dietary guidelines in pregnancy.
Women should be advised to take a daily supplement of 400 micrograms (400µg/0.4mg) folic acid at least 4 to 12 weeks prior to conception and during the first 12 weeks of pregnancy.
Iron, calcium, vitamin D and long chain omega-3 polyunsaturated fatty acids are particularly important nutrients throughout pregnancy.
Starchy carbohydrates, such as whole grains and fibre rich foods including breads, cereals potatoes, pasta and rice, six or more servings a day from this group; (Where one serving is 1 bowl of cereal, 1 slice of bread or 1 medium potato • Fruit and vegetables, at least 5 or more servings a day; 1 serving is 1 medium sized fruit e.g. 1 apple or 3 dessert spoons of vegetables.)
Dairy Foods as milk, cheese and yoghurt, three servings a day from this group; one serving is 125g yoghurt, 25g of cheese or 200ml milk.
Protein Foods include Meat, poultry, fish, eggs or legumes, at least 2 servings a day: Where one portion is 50-75g (2 -3oz) cooked meat, 100g (4oz) fish, 2 eggs or 6 dessert spoons beans.
Fats & Oils
Fats and oils are needed in small amounts. Limit to two portions a day: one portion is one heaped teaspoon of spread. In addition, one teaspoon per person of oil can be added in cooking (rapeseed oil or olive oil).
FOOD TO AVOID
The expert advised that pregnant women should avoid foods high in Fat and sugar.
Adequate energy intake is essential to promote full development potential of the unborn baby, while providing adequate energy for the mother.
Inadequate maternal energy intake will result in reduced maternal weight gain during pregnancy, which in turn may result in restricted fetal growth and later infant development.
Inadequate weight gain during pregnancy is associated with small for gestational age infants and preterm delivery.
Conversely, excessive maternal weight during pregnancy is associated with large for gestational age infants, macrosomia (big babies usually more than 4.5kg on scan), a higher caesarean section risk, in addition to a greater incidence of neonatal infection, hypoglycaemia and respiratory distress.
Additionally, large for gestational age infants are at a greater risk of developing childhood obesity, and hence a wide range of metabolic complications in childhood and later life.
Furthermore, rates of miscarriage are higher in obese women, as is gestational diabetes, hypertension and deep vein thrombosis, gestational age babies in particular if they have other complications such as hypertension.
Energy requirements in pregnancy vary widely between individuals it has been estimated that women will require an additional 5% in the first trimester, 10% in the second trimester and 25% in the third trimester.
For those of us who like specific details, it is important to know that based on a well-nourished woman with a normal BMI this intake equates to an additional 70kcal per day in the 1st trimester, 260 kcal per day in the second and 500kcal a day in the third trimester.
When choosing foods to increase energy intake, focus should be given to foods which are rich in essential vitamins and minerals such as milk and milk products, high fibre foods, lean red meat, omega-3-rich fish and fruits and vegetables.
Expectant mums should be encouraged to consume a diet which will meet all her recommended nutritional intakes, rather than focusing on energy intake alone.
Overweight or obese women should be encouraged to replace energy dense snacks with nutritious snacks.
Protein is essential in the development of a healthy baby as it forms the structural basis for all new cells and tissues in the mother and fetus. It is important to ensure the adequate balance of protein to energy as high protein alone can cause harm to the fetus.
Balanced intake of energy and protein seems to improve fetal growth (Ota et al, 2012). However, evidence is emerging on the relationship between the type of protein and fetal growth. Consumption of processed meats (such as sausage, burgers and chicken nuggets) increases the risk of small for gestational age babies while fish and eggs seem to reduce the risk.
Choosing foods high in fat, salt and sugar, seems to further increase risk of small for gestational age baby.
Most women will meet their requirements for protein as the typical population intakes are adequate for pregnancy with two servings of protein a day.
Women who have experienced nausea or vomiting of pregnancy are likely to have reduced their intake of protein rich foods due to aversions resulting from vomiting in early pregnancy.
Vegetarian women should be encouraged to consume adequate protein sources during pregnancy by increasing their intake of foods rich in protein including beans, lentils, chick peas, tofu, dairy products and eggs.
Vegetarian women should be advised on the importance of adequate protein sources to ensure optimal intake of essential amino acids, for example combining cereals and legumes in a meal.
The adequacy of dietary iron intake should also be addressed within this group. Women following a vegan diet may need dietetic review to ensure nutritional adequacy.
Women from lower socioeconomic groups are at higher risk of inadequate protein intake due to the associated costs. They are also more likely to choose less expensive processed foods which would put them at risk of small for gestational age babies.
If purchased in a multiple supermarket, a healthy diet costs 15-30% of the household budget for a family of 4 living on social welfare.
Pregnant women should be encouraged to consume two portions of protein rich foods a day and avoid processed versions such as sausages, luncheon meats etc.
Fats Dietary fat is an important energy source, and provides and aids in the absorption of fat soluble vitamins. However, high fat diets should be avoided during pregnancy due to the risk of excessive weight gain.
Long chain Omega 3 polyunsaturated fatty acids (PUFA) Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are two important long chain omega-3 PUFA.
DHA in particular is important for the developing fetus and there is evidence to support DHA consumption in pregnancy. DHA has been linked to improved retinal development for the developing fetus (baby).
The best sources of DHA are trout, salmon, mackerel, artic char and sardines.
Certain types of fish can be a source of environmental contaminants such as methylmercury.
High levels of methylmercury may be harmful to the developing fetus. Therefore pregnant women should avoid the consumption of marlin, shark, ray and swordfish and limit consumption of tuna to one serving of fresh tuna (150g), or two 240g cans of tinned tuna per week.
Folate/ Folic acid Folate is a B vitamin which is referred to as folic acid in the synthetic form. A daily supplement of 400 micrograms (400µg/0.4mg) folic acid as recommended prior to conception and for the first 12 weeks of pregnancy, has been shown to help prevent neural tube defects (NTD‟s).
Women who have a family history of NTDs or pre-existing diabetes should be provided with a prescription of a higher dose of folic acid prior to conception through 12 weeks gestation.
For women taking anti-seizure medication the requirement for folic acid may be different and they should be advised to consult their doctor. I would advice they take folic acid 5mg up to 12 weeks in to their pregnancy.
Thus, women should continue to eat foods rich in folate and folic acid throughout their pregnancy. These include green leafy vegetables, citrus fruit, whole grains, legumes and foods fortified with folic acid such as breads and cereals.
Women suspected of iron deficiency should have a full blood count (FBC) and if possible serum ferritin checked. Symptoms of iron deficiency are similar to some common problems of pregnancy such as fatigue.
Adequate dietary calcium intake before and during early pregnancy may reduce the risk or severity of pre-eclampsia and therefore adequate dietary intake should be encouraged.
During pregnancy women should be advised to consume 3 portions of dairy or calcium-fortified alternatives daily (FSA).
Adolescent pregnant mothers may require additional calcium which is best achieved with 2 additional portions of dairy (5 total) per day.
A portion is one glass of milk (200 ml), one pot of yoghurt (~125 ml) or a matchbox-sized piece of cheddar cheese (28g).
Whole milk, low-fat and skimmed milk all contain relatively similar levels of calcium and fortified milk is typically fortified.
Vitamin D can also reduce risk of adverse pregnancy outcomes including pre-eclampsia in addition to the classical bone disorders of rickets and osteomalacia.
Vitamin D is found naturally in few foods; dietary sources of this fat soluble vitamin include flesh of fatty fish, some fish liver oils (however fish liver oil should be avoided in pregnancy), and eggs from hens fed vitamin D.
Foods fortified with vitamin D such as margarine, milk and cereals are a good source of vitamin D in the diet.
However, the consumption of vitamin D rich foods, such as oily fish is not widespread and a vitamin D supplement is likely to be needed by most women during pregnancy to meet the required intake.
Pregnant women should be advised to take a pregnancy suitable supplement containing 5µg of vitamin D (5 micrograms/ 200IU).
The recommendation for Vitamin D is 10µg (10 micrograms/ 400IU) a day during pregnancy and lactation.
Of note, the majority of over-the-counter antenatal multivitamins contain 10 µg (10 micrograms/ 400IU) of vitamin D, therefore if a woman chooses to take a pregnancy multivitamin she will not require additional vitamin D supplementation.
If there is a history of rickets in a sibling or a known maternal vitamin D deficiency, a higher treatment dose‟ is warranted as the neonatal serum Vitamin D will be 60% of the maternal level, and both adequate maternal and neonatal serum levels are positively associated with bone health in childhood and later life .
Foods to Avoid
Caffeine: Caffeine is a mildly addictive stimulant which is found naturally occurring in foods and drinks such as coffee, tea and cocoa.
Caffeine is also used as an additive in soft drinks, energy drinks, some chewing gums and medications.
It is, therefore, possible that pregnant and lactating women may consume excessive caffeine from multiple sources.
Women are advised to limit caffeine to less than 200mg per day, which equates to 2-4 mugs of tea or 2 cups of coffee or 1000ml cola or 500ml energy drink or 4 bars of chocolate.
Caution should also be taken when prescribing medications that contain caffeine.
Vitamin A During pregnancy dietary intakes of vitamin A (retinol equivalent) greater than 7,000 micrograms may be teratogenic leading to an increased risk of congenital malformations.
Therefore, supplements containing pre-formed vitamin A, should be avoided. Due to the high levels of vitamin A contained in liver and liver products, e.g. cod liver oil, these foods should also be avoided.
Beta carotene is a precursor of Vitamin A (retinol) and is not harmful in pregnancy. Many food supplements will contain beta carotene as their source of Vitamin A.
To prevent food-borne illness, women should be advised to:
• Ensure eggs are cooked thoroughly, avoid soft eggs or raw eggs e.g. in mousse.
• Avoid un-pasteurised milk and any cheese or yoghurt made with unpasteurised milks.
• Avoid mould ripened cheese e.g. Camembert, Danish Blue, Brie, Stilton.
• Ensure all meat, fish and poultry is cooked throughout. Avoid smoked fish such as smoked salmon, cured and smoked meats e.g. salami.
• Wash all raw ingredients such as fruits, vegetables and pre-packed salads very well before eating.
• Keep raw and cooked meats separate, and use different knives, chopping boards and other kitchen utensils when preparing these foods to avoid cross-contamination.
• Ensure refrigerator temperature is below 5°C and put food in the refrigerator as quickly as possible. Freezer temperature should be below 18°C.
• Always wear gloves when gardening or changing cat litter, and always wash hands very well after these activities or handling animals or pets.
Dr. B. A. Alalade, MBBS DRCOG DFSRH RICR MPH Indiana University FRSPH
Alalade, Obstetrics & Gynaecology; Family, Sexual & Reproductive Health, Clinical Epidemiologist and Author
*Culled from the Institute of Obstetricians and Gynaecologists