Nutrition and pregnancy

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Pregnant woman eating fruit.

Nutrition and pregnancy refers to the nutrient intake, and dietary planning that is undertaken before, during and after pregnancy.

In a precursory study into the link between nutrition and pregnancy in 1950 women who consumed minimal amounts over the eight week period had a higher mortality or disorder rate concerning their offspring than women who ate regularly, attributed to the fact that the children born to well-fed mothers had less restriction within the womb.^[1]

Not only have physical disorders been linked with poor nutrition before and during pregnancy, but neurological disorders and handicaps are a risk that is run by mothers who are malnourished, a condition which can also lead to the child becoming more susceptible to later degenerative disease(s).^[2] 23.8% of babies are estimated to be born with lower than optimal weights at birth due to lack of proper nutrition.^[3]

It is very important that expecting mothers should change their personal habits like smoking, alcohol, caffeine, using certain medications and street drugs as soon as they know they are pregnant or even when they are planning to conceive. All these can affect the development of the organs like brain, which happen in early stages of pregnancy. They can cause irreparable damage to the growing foetus.^[4]

The expecting mothers should be very calm and peaceful, also focussed on what they should do for a healthy pregnancy.

Nutrition before pregnancy

Beneficial pre-pregnancy nutrients

As with most diets, there are chances of over-supplementing, however, as general advice, both state and medical recommendations are that mothers follow instructions listed on particular vitamin packaging as to the correct or recommended daily allowance (RDA).

• Magnesium and zinc supplementation for the binding of hormones at their receptor sites.
• Folic acid supplementation, or dietary requirement of foods containing it for the regular growth of the follicle.
• Regular vitamin D supplementation decreases the chances of deficiencies in adolescence. More importantly, it is known to reduce the likelihood of rickets with pelvic malformations which make normal delivery impossible.
• Regular vitamin B12 supplementation, again is known to reduce the chances of infertility and ill health.
• Omega-3 fatty acids increase blood flow to reproductive organs and may help regulate reproductive hormones.^[5] Consumption is also known to help prevent premature delivery and low birth weight.^[6] The best dietary source of omega-3 fatty acids is oily fish. Some other omega-3 fatty acids not found in fish can be found in foods such as flaxseeds, walnuts, pumpkin seeds, and enriched eggs.^[5]

Nutrition during pregnancy

The conception and the subsequent weeks afterwards is the time when it is at its most vulnerable, as it is the time when the organs and systems develop within. The energy used to create these systems comes from the energy and nutrients in the mother's circulation, and around the lining of the womb, such is the reason why correct nutrient intake during pregnancy is so important.

During the early stages of pregnancy, since the placenta is not yet formed, there is no mechanism to protect the embryo from the deficiencies which may be inherent in the mother's circulation. Thus, it is critical that an adequate amount of nutrients and energy is consumed. Additionally, the frequent consumption of nutritious foods helps to prevent nausea, vomiting, and cramps.^[7] Supplementing one's diet with foods rich in folic acid, such as oranges and dark green leafy vegetables, helps to prevent neural tube birth defects in the baby. Consuming foods rich in iron, such as lean red meat and beans help to prevent anemia and ensure adequate oxygen for the baby.^[8] A necessary step for proper diet is to take a daily prenatal vitamins, that ensure their body gets the vitamins and minerals it needs to create a healthy baby. These vitamins contain folic acid, iodine, iron, vitamin A, vitamin D, zinc and calcium.^[9]

By pregnancy trimester

First trimester

The first necessary step for proper diet is to take a daily prenatal vitamins, that ensure their body gets the vitamins and minerals it needs to create a healthy baby. These vitamins contain folic acid, iodine, iron, vitamin A, vitamin D, zinc and calcium. Hence the diet should consist of fruits, vegetables, non fat dairy foods, lean meat and whole grains which are rich in the prenatal vitamins and minerals. Eating well is very important during pregnancy, the food they eat keeps them and their baby nurtured. It should be right balance of carbohydrates, fat and protein without too much of calories. Drink fruit juices with 100% fruit and limit them to one glass per day. Juices are not only high in calories but do not provide the amount of fibre compared to a whole fruit. Include at least one serving of citrus fruit like orange, grape fruit as they are rich in vitamin C. Vegetable servings should include a variety of green leafy (broccoli, spinach, kale); red (tomatoes, red peppers); yellow (yellow peppers, corn) and orange vegetables (carrot, sweet potatoes, pumpkin). They should have at least 3 - 4 servings each day of fruits and 3 - 5 servings of vegetables each day during their first trimester. The foetus requires more of vitamins and minerals during the first trimester than extra calories. If the mothers are very hungry there is no harm in eating more food compared to their intake before pregnancy. It is a mandatory for the expecting mothers who by their obstetrician are very thin. Organic fat and protein build healthy babies. Succumbing to junk food will only deplete them of vital nutrients which is not at all advisable at that time.^[10]

Nausea and vomiting

Nausea and vomiting are one of the main symptoms faced by pregnant women. The most important thing to help control nausea during pregnancy is to not allow the stomach to become empty. It is better to eat snacks at small intervals rather than eating three large meals in a day. During nausea, the woman will not want to eat, but if food is not consumed regularly, then blood sugar levels can drop and actually increase nausea during pregnancy.^[11] Other ways to avoid nausea and vomiting include:

1. drink a lot of water with a pinch of Celtic sea salt which will aid hydration and replace the lost electrolytes. Table salt is known to bloat, hence sea salt is recommended.
2. Vitamin B6 is known to treat nausea, and food items like beef, tuna, banana, chicken, liver, avocados and whole grains.
3. Ginger also will have the similar effect on nausea as vitamin B6, hence raw ginger chopped into food or blended with tea will help relieve nausea and vomiting.^[12]

Lack of rest and taking a lot of stress has negative impact on their bodies. It can increase nausea during pregnancy, a very relaxing massage and stress relieved mind will help them to control nausea. Sleep and rest is very important.^[13] Eating fruits and vegetables, could reduce pregnant women's risk of developing an upper respiratory tract infection (URTI).^[14]

Exercise and Diet

If they were into vigorous exercise before pregnancy and continue to do so during their pregnancy then they should take the same diet for 1st trimester and increase their diet intake by 300 calories for their second trimester.^[15] A known fact is that regular exercise during pregnancy can improve posture also help in decreasing discomforts such as backaches and fatigue. Physical activity may help in prevent Gestational diabetes, relieve stress, and build more stamina needed for labor and delivery. The heart rate should not exceed beyond 140 beats per minute while exercising, overdoing the exercises will increase the fatigue rather than cure it. Hence expectant mothers should not revert to their vigorous exercise schedule before pregnancy.^[16]

Second Trimester

Second trimester is a crucial stage in pregnancy, hence the diet should include all essential food groups that are carbohydrates, proteins, fats along with already consuming vitamins and minerals. Increase the consumption of fruits and vegetables to 4 - 5 servings of each, which is more compared to your first trimester. Many women suffer from constipation in their second trimester, hence fibre rich food helps in easing the bowel movement and relieves constipation.Try reducing fat intake in the diet plan, along with sugar, both will lead to increase in excess weight than required.Weight gain is unhealthy for pregnancy in this stage. Consume sufficient amount of dairy products that are rich in calcium, very healthy and essential mineral for the baby.^[17]

Third Trimester

Third trimester is the time when the baby is fully developed and the mother is getting ready for labour. Hence nutrient same as before should be continued, along with 300 calories extra per day to keep the mother energized. Drinking between the meals should be reduced as the pressure on bladder increases by the growing foetus inside the womb. Diet plan should be more or less same as the second trimester only increased quantities to suffice the exhaustion and tiredness face by the mother. Proteins can be found in fish also, but it is necessary to enquire from the doctor regarding which fish is best for the mother and baby,for example : Many ladies are advised against swordfish and salmon. For teeth and bone development of the baby skimmed milk, cheese and yoghurt should be consumed, as they are enriched with calcium. One glass of skimmed milk or low fat milk is a healthy option.^[18]

Edema

Most pregnant ladies suffer from swelling in their third trimester, a condition termed as edema. Consumption of sodium rich food items should be avoided. It is estimated about 75% of women experience it. The most effective ways to relieve from excess swelling and related discomforts is

• Avoid elastic topped socks or knee high stockings, try wearing support panty hose instead.
• Wear comfortable shoes, slip ons are the best type.
• Avoiding standing for long hours and try moving around. Keep your leg elevated whenever possible.
• Hydrotherapy; lying in a pool helps in relieving the body of excess fluids and still protecting the uterus.
• Excess or low amount of salt level in the body cause swelling, hence moderation is necessary.^[19]

Potentially harmful determinants during pregnancy

It is advised for pregnant women to pay special attention to food hygiene during pregnancy in addition to avoiding certain foods in order to reduce the risk of exposure to substances that may be harmful to the developing fetus. This can include food pathogens and toxic food components, alcohol, and dietary supplements such as vitamin A.^[6]

Dietary vitamin A is obtained in two forms which contain the preformed vitamin (retinol), that can be found in some animal products such as liver and fish liver oils, and as a vitamin A precursor in the form of carotenes, which can be found in many fruits and vegetables.^[6] Intake of retinol, in extreme cases, has been linked to birth defects and abnormalities. However, regular intake of retinol is not seen as dangerous. It is noted that a 100 g serving of liver may contain a large amount of retinol, so it is best that it is not eaten daily during pregnancy, something which is also the same with alcohol intake in binge drinking.

Excessive amounts of alcohol have been proven to cause fetal alcohol syndrome. The World Health Organization recommends that alcohol should be avoided entirely during pregnancy, given the relatively unknown effects of even small amounts of alcohol during pregnancy.^[20]

Pregnant women are advised to pay particular attention to food hygiene and to avoid certain foods during pregnancy in order to minimize the risk of food poisoning from potentially harmful pathogens such as listeria, taxoplasmosis, and salmonella. Pregnant women are therefore advised to avoid foods in which high levels of the bacteria have been found, such as in soft cheeses. Listeria are destroyed by heat and therefore pregnant women are advised to reheat ready-prepared meals thoroughly. Pregnant women should also wash their fruit and vegetables very thoroughly in order to minimize risk. Salmonella poisoning is most likely to come from raw eggs or undercooked poultry.^[6] Maternal obesity has a significant impact on maternal metabolism and offspring development.^[21] Insulin resistance, glucose homeostasis, fat oxidation and amino acid synthesis are all disrupted by maternal obesity and contribute to adverse outcomes.^[21] Modification of lifestyle is an effective intervention strategy for improvement of maternal metabolism and the prevention of adverse outcomes.^[21]

Recommended nutrients during pregnancy

Folate

Folic acid, which is the synthetic form of the vitamin folate, is extremely critical both in pre-and peri-conception.^[6] Deficiencies in folic acid may cause neural tube defects; women who had 4 mg of folic acid in their systems due to supplementing 3 months before childbirth significantly reduced the risk of NTD within the fetus. This is now advocated by the UK department of health, recommending 400 µg per day of folic acid.

The development of every human cell is dependent on an adequate supply of folic acid. Folic acid governs the synthesis of the precursors of DNA, which is the nucleic acid that gives each cell life and character. Folic acid deficiency results in defective cellular growth and the effects are most obvious on those tissues which grow most rapidly.^[26]

Acute lymphoblastic leukemia

Along with neural tube development, folate affects DNA synthesis in multiple ways. Folate is involved in the construction of purines and pyrimidines, the building blocks of nucleic acids.^[27] Folate is also necessary to make s-adenosylmethionine (SAM), which acts as a methyl donor in the synthesis of DNA.^[27] Because of its role in these important mechanisms, fetal DNA would be significantly altered if a maternal folate deficiency is present. One possible outcome is DNA mutation, which could prevent normal gene expression. For example, a tumor-suppressing gene might be turned off, altering normal immune function in preventing cancer growth.^[27] Thompson et al.^[28] examined the relationship between maternal supplementation of folate and iron during pregnancy and incidences of acute lymphoblastic leukemia (ALL) in their children. Increased rates of ALL were found in children whose mothers did not take iron and folate supplements. Iron alone did not seem to reduce the risk of developing ALL, however iron in combination with folate was shown to have a protective effect in decreasing the risk for ALL. Thompson and his associates (2001), concluded that maternal folate supplementation throughout pregnancy plays an important role in reducing the risk for childhood ALL.^[28]

Water

During pregnancy, one's mass increases by about 12 kg.^[29] Most of this added weight (6 to 9 L) is water^[29] because the plasma volume increases, 85% of the placenta is water^[30] and the fetus itself is 70-90% water. This means that hydration should also be considered an important aspect of nutrition throughout pregnancy. To ensure healthy hydration during pregnancy, the European Food Safety Authority recommends an increase of 300 mL per day compared to the normal intake for non-pregnant women, taking the total adequate water intake (from food and fluids) to 2,300 mL, or approximately 1,850 mL/ day from fluids alone.^[31]

Nutrition after pregnancy

Proper nutrition is important after delivery to help the mother recover, and to provide enough food energy and nutrients for a woman to breastfeed her child. Women having serum ferritin <= 70 µg/L may need iron supplements to prevent iron deficiency anaemia during pregnancy and postpartum.^[32][33]

During lactation, water intake needs increase to compensate for the loss of water through milk production. Milk is made of 88% water, and the European Food Safety Authority therefore recommends that breastfeeding women increase their water intake by about 700 mL/day, giving an adequate volume of 2,700 mL/day (from food and drink), or approximately 2,200 mL/day from fluids.^[31]

Cravings and Aversions

As the weeks pass by, cravings or aversions for certain variety of food grows for pregnant ladies. These cravings or aversions should be controlled and consumed in required amounts. If they crave chocolates, then they should buy best quality chocolates and consume little amount of it every day and if they have aversion for meat, then they should have some other source for their protein or else consume meat in required quantities for necessary proteins and nutrients. Cravings for non food items like laundry starch, clay, etc. should be informed to the doctor immediately as they may have developed a medical condition called pica, which can be dangerous for them and their baby. These cravings and aversions are also a sign showing what are the required by the body and what should be avoided by the body.

References

See also

• Smoking and pregnancy

Further reading

• "Nutrition During Pregnancy Resource List for Consumers". USDA NAL Food and Nutrition Information Center. http://www.nal.usda.gov/fnic/pubs/bibs/topics/pregnancy/pregcon.pdf. 
• Health Education Authority (1996) Folic acid - what all women should know (leaflet) London:HEA