The Importance of Nutrition in Pregnancy

Good nutrition before and during pregnancy can have lifelong effects on your baby's health. This article covers the key nutrients — including folate, choline, iron, iodine, vitamin D and omega 3 — and how diet and exercise can support a healthy pregnancy.

The Importance of Nutrition in Pregnancy

Pre-conception and pregnancy are hugely important stages of life as this is a time when the nutrition of one person can have lifelong impacts on the developing baby. Nutrient shortfalls and deficiencies which may only create minor, short-term symptoms in the mother may have lasting effects on many aspects of health for the unborn child, potentially lasting into adulthood.1 Evidence suggests that nutrition in the first 1000 days of life, from the point of conception, can affect lifelong health, influence the development of disease, and may be associated with the development of cardiovascular disease and type 2 diabetes.2,3

National Diet and Nutrition Surveys in the UK already indicate that many women have an insufficient intake of some vitamins and minerals from their diets and these include folate, iron, choline and zinc.4 Given that the requirements for some of these nutrients increases during pregnancy, some women are not starting pregnancy well prepared, nutritionally.

Folic Acid

One of the best-known vitamins linked to pregnancy is folate or folic acid. This nutrient is part of the B vitamin group and is also referred to as vitamin B9. There are several forms of this nutrient, with folate being the most common form found in foods and folic acid commonly used in supplements. Both forms require conversion to a biologically active compound called 5MTHF before it can be used by the body.

During pregnancy, cells divide rapidly, and those of the neural tube need folate to form as they should. Many studies have found that a higher blood level of folate decreases the risk of neural tube defects (NTDs).5 Troublingly, NDNS indicate that 90% of women of childbearing age have folate levels low enough to increase the risk of NTDs.

Also concerning for those planning a pregnancy or who are already pregnant is the data which suggests that 1 in 3 women cannot metabolise folic acid or folate from foods sufficiently, which can further increase the risk of low folate status and NTDs.

Poor folate status can also lead to higher levels of a compound called homocysteine in the blood. This compound is associated with a variety of pregnancy complications including early pregnancy loss, growth restriction, pre-eclampsia, pre-term delivery and gestational diabetes.6,7 Given the importance of adequate folate in the red blood cells, it is important for those planning a pregnancy to follow the government's advice of taking 400µg of folate a day. Using the methylated form of this nutrient is advisable, as it raises folate levels 46% more than folic acid in a 12-week period.8

Choline

Another nutrient closely related to NTDs is choline, an essential nutrient most closely related to the B vitamins. Again, evidence suggests that even prior to pregnancy, choline intakes in women are below what is optimal. Choline requirements increase by 20% in pregnancy and 30% during breastfeeding9 and intakes fall significantly short of this requirement. Increasing choline intake has been shown to decrease the risk of NTDs by as much as 50%.10

Choline is also a key nutrient in brain development and normal liver function in the foetus as well as in exclusively breast-fed babies, with evidence showing that memory, processing speeds and recognition are better in infants whose mothers have a higher intake of choline.11

Iron

Iron deficiency is one of the most common nutritional deficiencies in pregnancy, which is unsurprising as, according to NDNS, 90% of menstrual age women do not meet the daily requirement for this mineral from their diets. More iron is required during pregnancy to allow for a greater maternal blood volume to support the placenta and foetus.12 Ensuring an adequate iron intake during pregnancy is also important to counteract the losses which occur during and immediately after delivery and minimise the risk of any complications. Low iron status after birth can also lead to symptoms such as poor cognition and depression in the mother.13 Adequate iron status and intake is required for normal growth as well as brain development in the foetus.14

Iodine

Iodine is also of high importance at this time as requirements for iodine increase to meet higher maternal needs and foetal requirements.15 It is essential to produce thyroid hormones which then regulate brain and neural development. Iodine excretion also increases via the kidneys during pregnancy.16 NDNS suggest that over 40% of women failed to meet the recommended intake of iodine in 2010, and more recent updates show that iodine intakes have decreased further in the decade since then.17 Low iodine status was associated with a lower IQ at the age of 8 years and lower reading accuracy and comprehension at age 9 years.18,19

Vitamin D

Vitamin D is another nutrient vital for normal pregnancy and beyond, as it can affect most cells of the body.20 Whilst bone health in both mother and foetus is probably best understood, there is evidence linking low vitamin D status to an increased risk of hypertension, pre-eclampsia and gestational diabetes, as well as preterm birth and low birth weight. One study from 2023 showed that the link between low vitamin D status as a predictor for pre-term birth is particularly significant for black women, due to their lower ability to make vitamin D from sunlight.21

There are also associations between low maternal vitamin D and increased risks of developing conditions such as asthma, eczema and allergies in childhood.

Choosing a multivitamin and mineral product which provides relevant nutrients, along with a good level of choline, is vital and it is also important to ensure that it is free from vitamin A and suitable to use prior to conception, during pregnancy and breastfeeding.

Magnesium

Magnesium is another mineral which is of concern for women, as over 70% do not meet the daily requirement for this mineral. Magnesium contributes to over 300 processes in the body including normal muscle function, normal energy production and normal bones and teeth. Magnesium levels decrease during pregnancy and magnesium insufficiency has been linked to leg cramps,22 pre-term labour23 and pre-eclampsia.24 There is also evidence to suggest that low intakes and blood levels of magnesium during pregnancy may affect the health of the child later in life. A magnesium supplement should be considered alongside a multivitamin if there is not a suitable level included, and magnesium citrate or bisglycinate forms are good options which have been shown to be better absorbed than some other magnesium salts.25

Diet

A Mediterranean style diet has been shown to be one of the best diets to follow for many areas of health. It focuses on polyphenol, potassium and magnesium rich fruits and vegetables, foods such as nuts and seeds which contain both omega 3 and 6 fatty acids, olive oil and lean meats and oily fish, such as herring, mackerel, salmon, and sardines which are also rich in omega 3 fats. Processed foods are discouraged, and the emphasis is on the consumption of fresh, unprocessed, or minimally processed foods which are naturally much lower in sugar, salt, and trans and hydrogenated fats. Recent evidence also shows that the Mediterranean diet can be useful for pregnancy, with studies showing that following it closely during pregnancy can reduce the risk of pre-eclampsia by 20%26 and improve the neurodevelopment of the child when measured at 2 years old.

Omega 3

As the NHS advises that frequent intake of oily fish is avoided due to concerns regarding environmental contaminants, and as NDNS data shows that the intake of oily fish is low, a fish oil supplement should be considered. Higher intakes of omega 3 fatty acids have been associated with a lower risk of pre-term and premature delivery and low-birth weight infants.27,28 Choosing a fish oil supplement which is screened for toxins and undergoes an extensive purification process, or an algal alternative, will ensure an adequate intake of the important omega 3 fatty acids.

Exercise

Exercise is also an important lifestyle consideration which can have a significant effect on health during pregnancy and pregnancy outcomes29,30,31 and should be of no risk to a normal, single pregnancy. Exercising regularly is associated with:

  • Up to a 90% reduction in the risk of developing gestational diabetes32
  • Reduction in urinary incontinence
  • Reduced risk of C-section and increased chance of a normal delivery33
  • Lower risk of high blood pressure and pre-eclampsia34
  • Reduction of back and pelvic pain35
  • Fewer feelings of anxiety and decrease in pre-natal depression36
  • Shorter labour37

Several studies also indicate an association between exercise in pregnancy and cognitive development, including increased IQ scores, language development, academic and sports performance and improved neuromotor skills, which can last well into childhood and adolescence.38

References

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  6. Gaiday AN, Tussupkaliyev AB, Bermagambetova SK, et al. Effect of homocysteine on pregnancy: A systematic review. Chemico-Biological Interactions. 2018;293:70–76.
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  9. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B-6, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, D.C.: National Academy of Sciences; 1998. pp. 390–422.
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