Heath Notes

Preeclampsia

Also indexed as: Pregnancy-Induced Hypertension [PIH], Proteinuric Gestational Hypertension, Toxemia (Pregnancy)

Mother-to-be? Protect yourself and your baby from the serious complications associated with this pregnancy problem. According to research or other evidence, the following self-care steps may be helpful:

Get routine checkups
Visit your prenatal provider regularly to prevent and control preeclampsia

Load up on lycopene
Take 4 mg a day of lycopene supplements to reduce the risk of preeclampsia

Consider calcium
Reduce your risks by taking 1,200 to1,500 mg a day of this essential nutrient

Don’t skip the salt
Use normal amounts of salt and drink more water to maintain normal circulation

These recommendations are not comprehensive and are not intended to replace the advice of your doctor or pharmacist. Continue reading the full preeclampsia article for more in-depth, fully-referenced information on medicines, vitamins, herbs, and dietary and lifestyle changes that may be helpful.

About preeclampsia

Preeclampsia is defined as the combination of high blood pressure (hypertension), swelling (edema), and protein in the urine (albuminuria, proteinuria) developing after the 20th week of pregnancy.¹ Preeclampsia ranges in severity from mild to severe; the mild form is sometimes called proteinuric pregnancy-induced hypertension² or proteinuric gestational hypertension.³

Women with even mild preeclampsia must be monitored carefully by a healthcare professional. Hospitalization may be necessary to enable close observation.⁴

The cause of preeclampsia is unknown, although several factors have been shown to contribute.⁵ ⁶ Preeclampsia is more common in women during their first pregnancy,⁷ as well as in women who are obese,⁸ ⁹ who have diabetes,¹⁰ or who have gestational hypertension.¹¹ ¹² ¹³ Women who have had preeclampsia during a previous pregnancy are also at increased risk.¹⁴ Preeclampsia has also been associated with calcium deficiencies,¹⁵ antioxidant deficiencies,¹⁶ ¹⁷ ¹⁸ older maternal age,¹⁹ and job stress.²⁰ ²¹ ²²

Product ratings for preeclampsia

Science Ratings	Nutritional Supplements	Herbs
	Calcium (for high-risk only)
	Folic acid Vitamin C and Vitamin E (in combination; for high-risk only)	Lycopene
	Fish oil Magnesium Vitamin B12 Vitamin B2 Vitamin B6 Zinc
Reliable and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit. For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

What are the symptoms?

Symptoms, which typically appear after the 20th week of pregnancy, include swelling of the face and hands, visual disturbances, headache, and high blood pressure. In severe preeclampsia, symptoms are more pronounced. Jaundice may also be present. Severe preeclampsia may lead to seizures (eclampsia) and may cause death to both mother and fetus if left untreated.²³ Like eclampsia, severe preeclampsia is a medical emergency requiring hospitalization.²⁴ ²⁵

Dietary changes that may be helpful

Unlike other conditions that cause high blood pressure, salt restriction and use of diuretics can worsen preeclampsia by reducing blood flow to the kidneys and placenta.²⁶ In preeclampsia, unrestricted use of salt and an increased consumption of water are needed to maintain normal blood volume and circulation to the placenta.²⁷

Data from one preliminary study suggest diets high in trans fatty acids are associated with an increased risk of preeclampsia.²⁸ Trans fatty acids are found in foods that contain partially hydrogenated vegetable oils, such as margarine. Foods that have been deep-fried (e.g., French fries) are also rich sources of trans fatty acids.

Lifestyle changes that may be helpful

Regular prenatal care is essential for the prevention and early detection of preeclampsia.

Job stress (lack of control over work pace and the timing and frequency of breaks) may be detrimental, and reducing job stress may be beneficial in the prevention of preeclampsia.²⁹ In a preliminary study, women exposed to high job stress were found to be at greater risk of developing preeclampsia and, to a lesser extent, gestational hypertension than were women exposed to low job stress. In this study, evaluation of job stress was based on scores assessing on-the-job psychological demand and decision-making latitude. High stress was defined as high psychological demand with low decision latitude, and low stress was defined as low-demand, high-latitude.³⁰

For women with preeclampsia, obstetricians and midwives often recommend bed rest and lying on the left side; this position helps reduce edema and lower blood pressure by increasing urinary output.³¹ However, a review of clinical trials concluded that bed rest can significantly worsen pregnancy-induced hypertension.³² Women with preeclampsia should discuss the pros and cons of bed rest with their doctors.

Other therapies

Other treatment for preeclampsia includes strict bed rest, maintenance of normal salt intake, intravenous magnesium sulfate, and possibly hospitalization for observation. The definitive conventional treatment of preeclampsia is induced delivery or cesarean section.

Vitamins that may be helpful

Calcium deficiency has been associated with preeclampsia.³³ In numerous controlled trials, oral calcium supplementation has been studied as a possible preventive measure.³⁴ ³⁵ ³⁶ ³⁷ While most trials have found a significant reduction in the incidence of preeclampsia with calcium supplementation,³⁸ ³⁹ ⁴⁰ ⁴¹ ⁴² ⁴³ some have reported no change.⁴⁴ One study reported that calcium supplementation reduced both the severity of preeclampsia and the mortality rate in the infants.⁴⁵

An analysis of double-blind trials⁴⁶ found calcium supplementation to be highly effective in preventing preeclampsia. However, a large and well-designed double-blind trial⁴⁷ and a critical analysis⁴⁸ of six double-blind trials⁴⁹ ⁵⁰ ⁵¹ ⁵² ⁵³ ⁵⁴ concluded that calcium supplementation did not reduce the risk of preeclampsia in healthy women at low risk for preeclampsia. For healthy, high-risk (i.e., calcium deficient) women, however, the data show a clear and statistically significant beneficial effect of calcium supplementation in reducing the risk of preeclampsia.⁵⁵ ⁵⁶ ⁵⁷

The National Institutes of Health recommends an intake of 1,200 to 1,500 mg of elemental calcium daily during normal pregnancy.⁵⁸ In women at risk of preeclampsia, most trials showing reduced incidence have used 2,000 mg of supplemental calcium per day.⁵⁹ Nonetheless, many doctors continue to suggest amounts no higher than 1,500 mg per day.

Women with preeclampsia have been shown to have elevated blood levels of homocysteine.⁶⁰ ⁶¹ ⁶² ⁶³ Research indicates elevated homocysteine occurs prior to the onset of preeclampsia.⁶⁴ Elevated homocysteine damages the lining of blood vessels,⁶⁵ ⁶⁶ ⁶⁷ ⁶⁸ ⁶⁹ ⁷⁰ ⁷¹ which can lead to the preeclamptic signs of elevated blood pressure, swelling, and protein in the urine.⁷²

In one preliminary trial, women with a previous pregnancy complicated by preeclampsia and high homocysteine supplemented with 5 mg of folic acid and 250 mg of vitamin B6 per day, successfully lowering homocysteine levels.⁷³ In another trial studying the effect of vitamin B6 on preeclampsia incidence, supplementation with 5 mg of vitamin B6 twice per day significantly reduced the incidence of preeclampsia. Women in that study were not, however, evaluated for homocysteine levels.⁷⁴ In fact, no studies have yet determined whether lowering elevated homocysteine reduces the incidence or severity of preeclampsia. Nevertheless, despite a lack of proof that elevated homocysteine levels cause preeclampsia, many doctors believe that pregnant women with elevated homocysteine should attempt to reduce those levels to normal.

Lycopene is a carotenoid found in tomatoes, watermelon, and several other foods. The concentration of lycopene in the blood has been found to be significantly lower in women with preeclampsia than in healthy pregnant women. In a double-blind trial, supplementation of pregnant women with lycopene significantly reduced the incidence of preeclampsia by 51.4%, compared with a placebo.⁷⁵ The amount of lycopene used was 2 mg twice a day; treatment was begun between the sixteenth and twentieth week of pregnancy and was continued until delivery.

A marginal zinc deficiency has been reported in some women with preeclampsia.⁷⁶ ⁷⁷ The common practice of prescribing iron and folic acid supplements to pregnant women can lead to reduced zinc absorption.⁷⁸ Trials studying the relationship between zinc supplementation and preeclampsia incidence have produced conflicting results. In one double-blind trial, the incidence of preeclampsia was significantly lower in women receiving a multivitamin-mineral supplement, which provided 20 mg of zinc per day, than in women who received the same supplement without zinc.⁷⁹ However, in another double-blind trial, a higher incidence of preeclampsia was reported in pregnant women given 20 mg of zinc per day than was reported in women given a placebo.⁸⁰ In yet another trial, zinc supplementation failed to prevent preeclampsia. ⁸¹ Therefore, current evidence does not sufficiently support the use of zinc as a way to protect against preeclampsia.

Fish oil supplementation has been proposed to lower the incidence of preeclampsia.⁸² ⁸³ However, controlled clinical trials suggest that fish oil does not reduce symptoms⁸⁴ or protect against preeclampsia.⁸⁵ ⁸⁶

Women with preeclampsia have been found to be depleted in antioxidants.⁸⁷ ⁸⁸ Some⁸⁹ ⁹⁰ but not all studies⁹¹ have reported deficiencies in vitamin C, vitamin E, and beta-carotene in preeclampsia patients. In a double-blind trial, supplementation of vitamin C (1 gram per day) and vitamin E (400 IU per day) reduced the incidence of preeclampsia by 76% in women at high risk.⁹² However, in another double-blind study that included women at normal risk of preeclampsia, supplementing with these same amounts of vitamins C and E resulted in a small increase (though not statistically significant) in the incidence of preeclampsia.⁹³ For women already suffering from this condition, supplementation with these same vitamins has led to only insignificant effects.⁹⁴

Magnesium deficiency has been implicated as a possible cause of preeclampsia.⁹⁵ ⁹⁶ ⁹⁷ ⁹⁸ ⁹⁹ Magnesium supplementation has been shown to reduce the incidence of preeclampsia in high-risk women in one trial,¹⁰⁰ but not in another double-blind trial.¹⁰¹

Women who are deficient in vitamin B2 (riboflavin) are more likely to develop preeclampsia than women with normal vitamin B2 levels.¹⁰² These results were observed in a developing country, where vitamin B2 deficiencies are more common than in the United States. Nevertheless, insufficient vitamin B2 may contribute to the abnormalities underlying the disease process.

Are there any side effects or interactions?
Refer to the individual supplement for information about any side effects or interactions.

References
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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires September 2008.

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