Nutrition and pregnancy
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Background
Nutrition and pregnancy refers to the nutrient intake, and dietary planning that is undertook before, during and after pregnancy. All dietary advice relating to pregnancy-related nutrition is noted by Mary E. Barasi as one of the major factors in determining the future well-being of a child conceived, some factors of a diet are even noted to reduce childhood morbidity and mortality due to helping the supply of nutrients to the mother. [2]
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, because children born to well-fed mothers had less restriction within the womb. [3]
Not only have physical disorders been linked with ill-nutrition before and during pregnancy, but neurological disorders and handicaps are a risk that is run by mothers who are mal-nourished, a condition which can also lead to the child becoming more susceptible to later degenerative disease(s). [4]
The following sections refer to the pertinence of nutrition throughout pregnancy, and are thoroughly researched enough to be usable for mothers or couples planning on conceiving.
Nutrition before pregnancy
Factors mitigating against pre-pregnancy nutrition
It is known that good nutrition before pregnancy is important because of the amount of "resources" childbirth requires. The process of pre-pregnancy nutrition is a process of "building up" the immune system in preparation of pregnancy, and is known as being one of the major factors in determining the success rate of conceiving healthy children.
As with most situations, the most important factor in pre-pregnancy nutrition is ensuring that the mother is healthy and without any major factors which could worsen the chances of conceiving, factors such as anorexia or bulimia are thought to be direct links with infertility; the minimum body mass index for conceiving mothers being 20.8.
This is also seen to be true with obese women with a BMI above 30 which is a direct result of decrementing amounts of insulin activity and sex hormones may reduce the viability of the ovum.
The ideal range of weight for women wishing to conceive children is thought to be optimal at body mass indexes between 20 and 26. If this, again, is used in conjunction with good nutrition and diet before pregnancy in terms of a normal balanced diet, then reserves of micronutrients, providing materials for pregnancy, would also be maximised.[5]
- For more information on how BMI is calculated, please refer to the body mass index article.
Major benefactors in pre-pregnancy diets
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.
Nutrition during pregnancy
Factors mitigating against nutrition during pregnancy
As it is known, the embryo at conception, and in 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, the placenta is not formed yet, so there is no mechanism to protect the embryo from the deficiencies which may be inherent in the mother's circulation, so it is critical that the correct amount of nutrients and energy are consumed.
One problem that was found in trials with pregnant women is that deficiencies in folic acid contributed towards neural tube defection; 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.
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.[6]
Beneficial factors against pre-pregnancy nutrition
During pregnancy, the most important factor could be seen as the amount of fat content within the woman when in the early stages of pregnancy. It is recommended, again that women who may be obese, should lose fat before trying to conceive a baby due to the infertility related to obesity.
Again, research has shown that women who have had optimal fat stores, and who were well-supplemented, had a much lessened experience in childbirth in regards to the energy and effort required during metabolic changes within the body, which was noted by monitoring leptin levels during pregnancy.
Recommended nutrients during pregnancy
| Nutrient | Recommendation (Extra = Above RDA) | Maximum/Total amount recommended per day |
| Energy | Increase by 200 kcal (840 kJ) per day in last trimester only. | RDA |
| Proteins | Extra 6 g per day | 51 g per day |
| Thiamin | Increase in line with energy; increase by 0.1 mg per day | 0.9 mg per day |
| Riboflavin | Needed for tissue growth; extra 0.3 mg per day | 1.4 mg per day |
| Niacin | Regular supplementation/diet of substance. No increase required. | RDA |
| Folate | Maintain plasma levels; extra 100 µg per day | 300 µg per day |
| Vitamin C | Replenish drained maternal stores; extra 120 mg per day | 50 mg per day |
| Vitamin D | Replenish plasma levels of vitamin 10 µg per day. | RDA |
| Calcium | Needs no increase | RDA |
| Iron | Needs no increase | RDA |
| Magnesium, zinc, and copper | Normal supplementation or consumption. | RDA |
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 who chooses to breastfeed her child.
References
- ^ Barasi, E. M., (2003) Human Nutrition - A Health Perspective . London : Arnold Publishing (ISBN 0340810254)
- ^ Rasmussen, K. M., (1992) The influence of maternal nutrition on lactation . Annual review of Nutrition 12, p103-117
- ^ UK Department of Health (1991) Dietary reference values for food energy and nutrients for the United Kingdom. - Report on Health and social Subjects No 41. report of the Panel on Dietary Reference Values of the Committee on Medical Aspects of Food Policy London:HMSO
- ^ Health Education Authority (1996) Folic acid - what all women should know (leaflet) London:HEA
- ^ World Health Organisation Framework for alcohol policy in the WHO European Region