This site is intended for health professionals only

At the heart of general practice since 1960

Practical GP advice on nutrition

Positive messages for nutrition in pregnancy

I think it is interesting that we give quite a lot of negative advice to women in pregnancy and I wonder what you feel might be a more positive message?

I think women should be given advice about eating five portions of fruit and vegetables a day. Advice should also be given about the energy intake in pregnancy. Many women feel they should 'eat for two' but the energy intake only increases in the second and third trimester by 240kcal per day, which is equivalent to a yoghurt and a piece of toast. More calories may be needed if the woman is still physically very active.

It is important to improve the quality of the diet in pregnancy, as the vitamin and mineral requirements go up. The iron intake should be increased; new recommendations by WHO in a forthcoming book will suggest routine supplements in the third trimester as

it is almost impossible to get enough from diet alone.

High levels of vitamin A (retinol) should be avoided in pregnancy. There is some debate over the level of intake above which there is a risk, it is thought that pregnant women should consume no more than 3300µg per day, doctors should advise pregnant women to avoid supplements containing vitamin A and eating liver. Some women discover they are pregnant and worry about the vitamin A they took before they realised they were pregnant. If they had kept to the reference nutrient intake (RNI, 700µg) there should not be cause for concern.

Long chain fatty acids affect brain development but many women do not fancy oily fish in pregnancy. Cod liver oil capsules should be avoided because they come from the liver and contain high levels of vitamin A, as well as dioxins which may be carcinogenic. Fish oil supplements that are not from cod liver oil are available.

Research by Professor David Barker has highlighted the importance of good nutrition during pregnancy. Barker's work suggests that maternal nutrition and the subsequent birthweight of infants may influence the risk of disease in later life. It has become evident that there are 'critical' periods in fetal life and infancy and that an early insult or injury during such periods could act as a programming factor resulting in long-term alteration in function of the body which could ultimately influence the pattern of disease in adulthood.

Barker hypothesises that undernutrition in pregnancy will retard embryonic growth resulting in low-birthweight infants. His initial studies, based on maternity and infant welfare records, revealed that babies born of low birthweight had significantly higher death rates from cardiovascular disease in later life. Subsequent studies have linked low birthweight to other disease such as diabetes.

What about diet when breast-feeding?

Breast-feeding imposes much greater nutritional demands on the mother than pregnancy. Apart from the standard healthy diet, a weight loss diet should not be followed. Enough carbohydrate is needed and an extra 550mg a day while breast-feeding. This means that mothers should try to eat more calcium-rich foods such as milk, cheese, yoghurts and green leafy vegetables.

Current advice is to avoid peanuts during breast-feeding as this could cause an allergic reaction in the infant. Some foods have been identified as colic-causing: onions, strawberries, peppers and grapes.

GP Dr Linden Ruckert and Mrs Joanna Peden discuss how GPs

can best offer nutritional advice

What's in this article

 · Positive messages for nutrition in pregnancy

 · Conflict around food should be avoided

 · Caution is needed with vitamin supplements

Rate this article 

Click to rate

  • 1 star out of 5
  • 2 stars out of 5
  • 3 stars out of 5
  • 4 stars out of 5
  • 5 stars out of 5

0 out of 5 stars

Have your say