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