September 2002

• The Benefit of Magnesium for Preeclampsia
• ERT and the Risk of Ovarian Cancer
• The Spread of West Nile Virus

The Benefit of Magnesium for Preeclampsia

Eclampsia and preeclampsia are the leading causes of death for pregnant women and their fetuses, particularly in developing countries. Physicians believe the high blood pressure, swelling, and protein in the urine associated with preeclampsia lead to the convulsions and coma of eclampsia.

Obstetricians generally use anticonvulsants to treat and prevent the convulsions of eclampsia. In the U.S., magnesium sulfate has been the drug of choice for nearly a century. Research confirms magnesium as the most effective drug at preventing eclamptic seizures. Now magnesium sulfate is being used increasingly to treat preeclampsia as well, with the hope it will prevent eclampsia. A study published in the June 1, 2002, issue of The Lancet confirms this hope.

The study, dubbed the Magpie Trial, was a large international effort aimed at discovering the effects of magnesium sulfate on women with preeclampsia and their children. Close to 10,000 women with preeclampsia from 33 developed and developing countries were involved. Roughly half of the women were randomly assigned to receive magnesium sulfate while the other half received a placebo.

Use of magnesium sulfate resulted in a 58% decrease in risk of eclampsia compared to use of the placebo. This translates to 11 fewer women in 1,000 suffering from eclampsia. The preventive effect of magnesium was consistent regardless of the severity of the preeclampsia, the stage of pregnancy, whether an anticonvulsant had been given prior to the trial, and whether the woman had delivered before entry into the trial. Women receiving magnesium sulfate also had a 45% lower risk of death than women receiving the placebo. There appeared to be no difference in the risk of fetal or infant death related to the use of either the drug or the placebo. However, women receiving magnesium sulfate had a 27% lower risk of premature detachment of the placenta.

While the benefits of using magnesium sulfate are evident, some non-serious negative side effects were also apparent. Roughly 25% of the women receiving the drug experienced flushing, nausea, or vomiting. Only 5% of the women receiving the placebo experienced side effects.

Based on the results of this study, magnesium sulfate may become a mainstay in the treatment for preeclampsia as well as eclampsia. The low cost of the drug makes this even more likely, not only in the U.S., but also around the world.

September 2002 Update

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ERT and the Risk of Ovarian Cancer

Another strike against hormone replacement therapy has emerged. The results of a study published in the July 17, 2002, issue of the Journal of the American Medical Association show women who take estrogen replacement therapy, particularly for an extended period, have an increased risk for ovarian cancer.

The study involved over 44,000 women enrolled in a nationwide breast cancer-screening program between 1979 and 1998. Follow-up interviews and questionnaires revealed 329 women in the study developed ovarian cancer over the 20-year period. Use of estrogen-only replacement therapy for any length of time was associated with an increased risk of ovarian cancer. The researchers found the results were consistent regardless of other risk factors for ovarian cancer, such as age, type of menopause (surgical or natural), and use of oral contraceptives. The risk of cancer also appeared to increase with the length of estrogen use; women who took estrogen for over 20 years had 3 times the risk of developing ovarian cancer. The results were similar in women who had a hysterectomy; such women are more likely to take estrogen for prolonged periods of time.

Women who have not had a hysterectomy are usually prescribed an estrogen-progestin combination to protect against endometrial cancer. Results of the study showed women taking short-term combined hormone therapy did not have an increased risk for ovarian cancer. However, women who took combined therapy after having taken estrogen-only therapy were still at an increased risk. The practice of taking combined hormone therapy is relatively recent; therefore, further time and study may be needed to accurately evaluate the risk of ovarian cancer associated with its use.

Combination therapy was the subject of controversy surrounding the Women’s Health Initiative, which found that such therapy increased risk for breast cancer, blood clots, and stroke. However, the estrogen-only arm of the study is still ongoing, having found no significant adverse effects.

The risk of ovarian cancer should not be considered lightly — this form of cancer causes more deaths than any other genital cancer. Ovarian cancer is also notoriously difficult to diagnose at an early stage. These factors, combined with the results of the study, add one more issue for women to consider when deciding whether to take or continue estrogen replacement therapy.

September 2002 Update

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The Spread of West Nile Virus

West Nile virus is a viral disease — spread by the bite of infected mosquitoes — that can cause encephalitis, an infection of the brain and spinal cord. It first appeared in the United States in 1999, when 55 people became seriously ill and another 7 died.

There was a total of 66 human cases of West Nile Virus in 2001 — mostly in New York, New Jersey, and Florida — nine of which were fatal. Almost all cases occurred in August and September, but a few were diagnosed between October and early December.

Since 1999, the geographic boundaries of the disease have spread as far north as Maine; as far west as Montana, Wyoming, Colorado, and New Mexico; and as far south as Florida and Texas. This is a dramatic change from 2000, when it was only detected in New York, New Jersey, and Connecticut. And 2002 has seen at least 480 human cases and 22 deaths from West Nile in the country's worst outbreak since the virus first was first detected here.

Most likely, the disease will continue to move west. To slow its progress, the CDC is concentrating on teaching people to avoid mosquitoes and their bites as much as possible. When in places where there is risk of mosquito bites:

• Use insect repellent containing DEET.
• Try to wear long-sleeved clothes and long pants treated with repellents containing permethrin or DEET; mosquitoes can bite through thin clothing. Do not apply permethrin repellants directly to skin.
• Whenever possible, stay indoors at dawn, dusk, and in the early evening, which are peak mosquito biting times.
• Eliminate standing water sources from around your home. These are popular places for mosquitoes to lay eggs.

Most people who become infected with West Nile virus will have either no symptoms or only mild ones. The risk of severe disease is higher for people over 50. There is no evidence that West Nile virus can be spread from person to person or from animal to person.

September 2002 Update

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