Doctors keep searching for a magic bullet to cure pre-eclampsia. But evidence suggests the best preventative is a good diet with ample amounts of all nutrients.
Pre-eclampsia is, according to the medical profession, an enigma. It has been known by many different names around the world. It has been called toxaemia, pre-eclamptic toxaemia (PET), pregnancy induced hypertension (PIH), hypertensive disease of pregnancy (HDP), metabolic toxaemia of late pregnancy (MTLP) and even gestosis. The overabundance of names should be enough to indicate a certain amount of confusion about what exactly it is and how it develops. Although most antenatal tests are designed specifically to look for signs of pre-eclampsia, nearly 30 per cent of cases are first detected in labour, either because they were missed by antenatal screening or because the condition did not manifest until then.
The first indication which doctors look for is hypertension (raised blood pressure). Should a woman also have raised levels of uric acid in the blood and oedema (swelling due to water retention), there is cause for concern. Together, these symptoms generally indicate pre-eclampsia; singly, they do not usually pose a threat.
If early symptoms of pre-eclampsia are left untreated, protein may eventually appear in the urine. Even diagnosing this can be hit and miss the dipsticks used to detect protein in a woman's urine have a 25 per cent false positive rate when only traces of protein are indicated (Enkin, M, et al. A Guide to Effective Care in Pregnancy and Childbirth, Oxford University Press, 1995).
When protein appears in a pregnant woman's urine, clots and fatty acids begin to build up in the placenta, interfering with its efficiency and eventually causing it to cease functioning altogether. When the placenta is not functioning properly, the baby is not getting essential oxygen and nutrients, and growth retardation is a real possibility. Under these circumstances the body may, as a survival mechanism, instigate labour prematurely.
In mild to moderate forms, pre-eclampsia does not pose a particular threat to either mother or baby particularly if carefully monitored. However, one in 2000 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.
Many years ago, it was believed that the symptoms were the result of toxic agents in the body, thus the name pre-eclamptic toxaemia. Other theories include the idea that some placentas have narrower blood vessels than others, thus predisposing the mothers to the disease; that in some mothers the immune system views the baby as a foreign body and is trying to reject it; and that what we call pre-eclampsia is a normal physiological adaptation to pregnancy.
But perhaps the single biggest factor which has been linked to pre-eclampsia is poor diet: if a woman is malnourished and living in a stressful environment, the risk is even greater. Unfortunately, many practitioners are ignorant of what constitutes a proper diet for pregnancy. When nutrition is studied, the research shows an obsessive focus on single nutrients, like magnesium, given in isolation, instead of a holistic dietary approach.
In the meantime, the published evidence on diet is very clear. The only clinicians who have managed to completely eradicate pre-eclampsia are those who have taken steps to ensure women are fed properly. This means receiving daily high protein in the form of milk, eggs and meat, as well as daily servings of leafy green vegetables and fruit. The daily calorie intake should be around 2,800 and should include 80-100 g of protein.
Common sense, some would say, yet so many doctors still recommend calorie and weight restriction during pregnancy, forgetting that a diet for pregnancy is not necessarily a diet for life. This tunnel vision may only worsen with a recent study which concluded that the "liberal" weight gain now recommended (25-35 pounds) during pregnancy is not necessary (Lancet, 1998; 351: 1054-5).
A century of observation proves nutritional therapists are on the right track. In 1893, Dr Pinnard in France noted: "Since using the milk diet in the treatment of pregnant women with oedema, proteinuria, headaches and visual disturbances, I have not come across one case of eclampsia in more than 5000 women." (Ann Ob Gyn, 1900: 12-13).
One famous study from nearly 60 years ago compared outcomes for two groups of 750 women, many of whom were malnourished before pregnancy. The group which received careful nutritional counselling and vitamin and mineral supplements had no cases of pre-eclampsia or eclampsia, compared with 64 cases in the control group. In addition, there was no prematurity (37 in the control group) and only three cases of infant death, compared with 41 in the control group (J Int Coll Surgeons, 1941, 4: 147-54).
In Australia, in 1952, Dr Reginald Hamlin achieved remarkable results in the Women's Hospital in Sydney with an energetic nutritional campaign. He made sure all new patients were lectured by the superintendent and dietician on the principles of good diet. They were told to adopt a high protein diet which included red meat, milk, eggs and fruit, and were given vitamins. He was also adamant that women attend their ante natal appointments. If they did not show up on the appointed day, he would sometimes send the police out to their homes to find out why. His methods were unconventional, but the results complete elimination of pre-eclampsia in the hospital could not be argued with (Lancet, 1952; i: 64).
Enter Dr Brewer
Dr Tom Brewer, an American obstetrician, is perhaps the most outspoken proponent of nutritional therapy for pre-eclampsia. Yet, Brewer's work has been all but ignored by the medical profession. Not because it doesn't work, but because Brewer himself is so outspoken about its benefits. Brewer wrote his first book about the benefits of dietary therapy in the treatment of pre-eclampsia back in 1966. His book, Metabolic Toxaemia of Late Pregnancy (Keats/Thorsons, 1982), remains a standard reference for anyone who rejects the "enigma" status of the disease and wishes to prevent or halt the progression of pre-eclampsia.
His work stems from noticing far higher rates of pre-eclampsia among his poorer, public clinic patients than among his better fed, private patients. Because of this, he started prescribing a liberal, high protein diet for his public patients in a deprived district of New Orleans,. As a result, he completely eradicated eclampsia and virtually eradicated pre-eclampsia from his practice.
This result has been confirmed in published papers, though, some would argue, not scientifically designed trials (J Green in Enkins, et al. Effective Care in Pregnancy and Childbirth, as above). It also has the backing of many women who, frustrated with the ineffectiveness of conventional treatment, choose to follow Brewer's diet.
Dietary red herrings
One of the reasons why the medical profession has concluded that dietary measures don't work is that its definition of "dietary measures" included only restrictive measures (weight gain, salt, fluids). There is plenty of evidence to show that restrictive regimens, far from preventing pre-eclampsia, may actually end up causing it (Baillieres Clin Ob Gyn, 1995; 9: 497-507).
For instance, routine weighing is so much a part of the ante natal regimen that it has largely escaped any kind of critical assessment. In a survey of the attitudes of general practitioners to routine weighing, it was revealed that most saw it primarily as a tool for detecting pre-eclampsia (BMJ, 1992; 304: 487-9). However, as the authors point out, pre-eclampsia can only be reliably diagnosed by measuring blood pressure and analysing urine for protein. While there is an association with greater than average weight gain in the second half of pregnancy and the disease, the weight gains of women with and without pre-eclampsia overlap to such an extent that weight gain in an individual woman is of little predictive value (Br J Ob Gyn, 1991; 98: 189-94; BMJ, 1957; i: 243-7) .
Also, weight gain in itself is not a reliable predictor of a healthy or unhealthy baby. Gaining 36 pounds on crisps and sodas will not ensure the health of a baby, as one reported story poignantly illustrates. After her daughter died of eclampsia, a mother contacted a pre-eclampsia support group. Eventually the advisor asked: "Did she eat well?" The mother answered: "Yes, she ate like a horse. . . chips, pies, sausages and pear drops. Loads and loads of pear drops." (PETS Newsletter, No 20).
Pregnant women also need to drink freely. Free intake of fluids helps to keep the kidneys working well, flushing waste products out of the system. The normal swellings of ankles, face, feet and hands which 80 per cent of women experience are not a cause for concern in a healthy, well nourished individual, and should not be confused with the pathological swelling that comes with pre-eclampsia.
Nevertheless, doctors sometimes prescribe diuretics to treat oedema. But diuretics deplete the body of essential salt and fluids, creating even more problems. Results from 10 randomised, controlled trials involving 7000 pregnant women showed that while diuretic treatment reduced hypertension and oedema, it did not prevent pre-eclampsia or reduce prenatal mortality (BMJ, 1985; 290: 17-23).
And what of restrictions on salt? Pregnant women need salt as much as any of us perhaps more. The greater volume of blood in a pregnant woman's body means that she will be sweating more and secreting greater quantities of salt through her sweat.
Salt helps to regulate the fluid balance in the body and is essential for the proper functioning of nerves and muscles. Historically, restriction of salt has not been shown to reduce the incidence of pre-eclampsia (Eur J Ob Gyn Reprod Biol, 1991; 40: 83-90).
This fact was underscored in 1958 when a study at St Thomas's Hospital in London revealed the dangerous consequences of restricting salt. In the study, 1000 women were told to decrease their salt intake, while another group of 1,019 were instructed to increase the salt in their diet. The women on low salt diets had much higher rates of pre-eclampsia and eclampsia, as well as higher rates of miscarriage, perinatal deaths, caesareans and other complications (Lancet, 1958; i: 178). With hindsight, this was a highly unethical trial, which resulted in unnecessary damage, trauma and deaths for many pregnant women and their babies.
Besides diuretics, the kinds of drugs used to treat pre-eclampsia include low doses of aspirin, tranquillisers, mood altering drugs, muscle relaxants (known as tocolytics) to forestall the onset of labour, drugs to reduce blood pressure (anti hypertensive drugs) and drugs to thin the blood (anti coagulants). There is very little evidence to show that any of them do much good (M Enkin, Effective Care, as above). What is more, doctors may be over reacting, since in pregnancies with mild to moderate pre existing essential hypertension, 90 per cent are associated with good maternal and neonatal outcomes (Compr Ther, 1995; 21: 227-34; Ob Gyn 1986; 67: 197-205).
Tranquillisers and tocolytics can depress the appetite, creating even more problems. Anti hypertensive drugs can help maintain a mother's blood pressure but cannot reduce it, nor can they prevent protein appearing in her urine, growth retardation, pre term birth or caesarean section.
But the most controversial treatment of all concerns low dose aspirin. Aspirin acts as an antiplatelet and anti coagulant. For the last 10 years, results of trials with aspirin have been mixed. At least one meta analysis concluded that low dose aspirin reduced the risk of pregnancy induced hypertension and severe low birth weight (JAMA, 1991; 266: 260-4). Another suggested that, while it may reduce the risk of hypertension , aspirin also increases the risk of abruptio placentae (the placenta peeling off the uterine wall) and does not reduce the risk of illness in the newborn (N Eng J Med, 1993; 329: 1213-8).
Still later trials have shown that it does not benefit either mother or baby. One, involving 1,066 women taking 50 mg aspirin daily showed no difference in outcome between those women treated with aspirin and those without (Lancet, 1993; 341: 396-400). Another revealed that women taking aspirin needed more blood transfusions after delivery (BMJ, 1994; 308: 1250-1). The most recent trial, however, has finally put the nail in aspirin's coffin. The study, involving 2,539 "high risk" women, showed that aspirin therapy just doesn't work and should now be abandoned, since it brings with it damaging side effects, such as stomach irritation, spontaneous bleeding and premature placental separation (New Eng J Med, 1998; 338: 701-5).
We need to be aware of bias and habit, even among those who espouse conventional treatment. For instance, in one randomised, controlled trial, women being cared for by obstetricians were 8.8 times more likely to be admitted to hospital for treatment and 11.4 times more likely to be diagnosed as having protein in their urine than those in a hospital day care unit (Lancet, 1992; 339: 224-7). There were no differences in anti hypertensive drug use between the groups. The obstetric group were also 4.9 times more likely to have labour induced. Although obstetricians have long justified their high intervention rates by claiming they look after a higher risk population, in this study there were no differences in Apgar scores, birth weight and rates of admission to neonatal intensive care units between the babies of the two groups, suggesting that aggressive treatment makes little difference.
Many doctors believe that nutrition is the stuff of home economics classes, not science. As a result, feeding pregnant women is a low medical priority long after prodding and scanning. There is also extreme social resistance, among men and women, to the idea. After all, women are supposed to feed their families, not be told what to eat.
Medicine can detect pre-eclampsia with varying degrees of success, but cannot cure it. Prevention is the only cure and nutrition appears to be the only prevention.
It behoves us to remember that eating for two refers not to quantity, but quality. Because the mother and baby are one large system, it is vital that women eat to their appetite and that the food they eat be of the best possible quality.
Pre-eclampsia is only the tip of the iceberg. Many adult illnesses can be traced back to the environment in the womb. Maternal nutrition, when viewed from this perspective, is neither fad nor fancy, but a profound responsibility.