Pat Thomas looks at nutritional ways of reducing the risks of pre-eclampsia.

Pregnant women and their health practitioners have come to fear pre-eclampsia. It occurs in about 5 per cent of pregnancies, and often strikes without warning.

Pre-eclampsia is a condition which adversely affects the way the placenta functions. In severe cases, it deprives the baby of essential oxygen and nutrients, resulting in poor growth and premature labour.

The symptoms are raised blood pressure, water retention and protein in the urine. All three of these symptoms must be present for a diagnosis of pre-eclampsia to be made. Antenatal tests are designed to detect pre-eclampsia in pregnancy, but nearly 30 per cent of cases are first detected in labour.

Mild to moderate forms of the condition, if carefully monitored, do not pose a threat. However, around one in 2,000 cases of pre-eclampsia can develop into eclampsia, a potentially lethal condition for both mother and baby. Early symptoms of eclampsia include severe headaches, flashing lights, nausea, vomiting and pain in the abdomen. In extreme cases, the mother may experience fits, convulsions and, more rarely, go into a coma and die.

Who is at Risk?

• smokers
• women carrying more than one baby
• those who currently have high blood pressure or who have a family history of high blood pressure
• women over 40
• women who suffer from migraines
• those with blood group AB
• those with impaired liver or kidney function
• obese women
• diabetics
• first-time mothers
• second-time – or more – mothers with a new partner (Your risk will the same as it was in your first pregnancy.)
• women exposed to high levels of toxins such as lead (common in some water supplies and in heavily polluted areas), which increases free radical production

Causes

Many years ago, it was believed that the symptoms of pre-eclampsia were the result of toxic agents in the body, hence the name pre-eclamptic toxaemia. Other theories included the idea that some placentas have narrower blood vessels than others, and so deprive the baby of essential nutrients. Some thought that it was an abnormal immune-system response, where the mother’s body saw the baby as a foreign body and tried to reject it.

As studies into the link between nutritional deficiencies and pre-eclampsia mount, the evidence is that poor diet plays a significant role in the development of the condition. Specialists at Guy's, Kings' and St Thomas' schools of medicine in London found that, if a woman is malnourished and living in a stressful environment, her risk is greater than normal. Those practitioners who have taken steps to ensure that women are adequately nourished have managed to eradicate pre-eclampsia.

For a pregnant woman, adequate nutrition means cutting back on anti-nutrients, including sugar. A full range of nutrients are needed to metabolise carbohydrates and, because sugar has calories but no nutrients, the body must draw the necessary components for metabolism either for your food or from body tissues.

Recent animal and human studies have also shown that sugar increases the amount of magnesium and other important minerals that are excreted in the urine. This means there is less for the body to use. The diet recommended by the Pre-Eclampsia Society (PETS) UK is low in sugar for this reason.

Another important factor is protein. An extra helping of milk, eggs and meat, as well as daily servings of fresh, leafy green vegetables and fruit, will reduce the risk of pre-eclampsia.

Taking supplements seriously

Apart from paying careful attention to diet, a woman who is at risk of pre-eclampsia should consider increasing her intake of certain important nutrients.

The recent study at Guy's, Kings' and St Thomas' schools of medicine in London showed that women at high risk of pre-eclampsia could avoid the condition by taking antioxidant supplements, namely vitamins C (1000mg daily) and E (400iu daily).

Several recent studies have suggested that free-radical damage may be at the heart of pre-eclampsia. Free radicals are the toxic by-products of body metabolism and, if they are allowed to build up, they can damage healthy cells and tissues. Antioxidants are able to neutralise free radicals, preventing them from causing damage to the body. The London researchers believe that women with pre-eclampsia may not be consuming enough antioxidant vitamins to help process the increased number of free radicals their pregnant bodies make.

Important nutrients which boost antioxidant levels include vitamin B6 (10-50mg daily), calcium (1000mg daily) and magnesium (400-600mg daily). On their own, none of these nutrients have been consistently shown to help pre-eclampsia. However, supplementing with all three, especially if combined with an improved diet, may help prevent the condition from appearing. They may also prevent the condition from getting worse if it has already appeared.

Two other useful supplements are zinc and essential fatty acids (EFAs). Zinc is important to support foetal growth, and your ideal daily intake should be around 30mg. The best way to get EFAs is through your diet. Make sure you are eating lots of oily fish such as salmon and mackerel or that you take 1000mg of omega-3 fatty acids each day.

Fighting stress

Stress can also play a big part in the development of pre-eclampsia. One recent Norwegian study found that women working in highly stressful and hectic work environments are nearly one and a half times more likely to develop pre-eclampsia than those who are not.

Stress raises catecholamine (stress hormone) levels. This in turn increases the production of free-radicals. Women working under these conditions might benefit from a nutritional programme designed to reduce free-radical damage, as well as instruction on stress-management, biofeedback or similar relaxation techniques.

What you can do

If you are at risk of pre-eclampsia, there are several positive things you can do, for example:

• Eat well and eat a variety of foods.
• Have an extra serving of a protein food each day
• Cut back on “anti-nutrients” such as sugar and saturated fats.
• Take a good quality multivitamin and mineral supplement and consider extra supplements of vitamins C and E (to bring your daily intake up to the effective level detailed above.
• Unless you are very obese, do not restrict you weight gain while pregnant. Instead take advice about sensible eating during pregnancy
• Drink to your thirst and salt to your taste
• Investigate ways to relieve stress through yoga, tai chi, meditation or a regular massage.

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