Published: Nov. 11, 2006
Updated: Nov. 12, 2006
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By Duke Medicine News and Communications
DURHAM, N.C. -- Women with systemic lupus who become pregnant are at significantly greater risk for death or other medical complications than are pregnant women without lupus, Duke University Medical Center researchers have found in a nationwide study of more than 18 million women.
The study, believed to be largest of its kind, suggests that pregnant women with systemic lupus should be considered a high-risk population and should be monitored closely by both a rheumatologist and an obstetrician who specializes in caring for high-risk patients, the researchers said.
"Pregnant women with lupus should never try to go through their pregnancy alone and simply hope for the best," said study leader Megan Clowse, M.D., M.P.H., assistant professor in the Division of Rheumatology. "They should stay in close contact with their doctors and report any problems immediately."
Clowse presented the findings on Sunday, Nov. 12, at the annual meeting of the American College of Rheumatology, in Washington, D.C. The study was funded by the National Institutes of Health's Building Interdisciplinary Research Careers in Women's Health program.
Lupus is an autoimmune disease in which the immune system loses its ability to distinguish between "self" and foreign substances and thus relentlessly attacks the body's own tissues and cells. Individuals with lupus often exhibit many different symptoms, including arthritis, kidney disease, rashes, fevers, anemia and sensitivity to light, among other problems.
Approximately 1.5 million Americans -- roughly 90 percent of them women -- have some type of lupus. Most patients are diagnosed during their reproductive years. Seventy percent of patients have systemic lupus, the most severe form of the disease.
All women with systemic lupus, pregnant or not, are at increased risk for death and medical complications compared to a healthy population, Clowse said. Other studies report that each year, between 0.8 percent and 3 percent of lupus patients die from the disease.
Previous research also has shown that pregnancy can increase the activity level of lupus, increasing the danger to the woman and sometimes causing problems in her fetus, according to Clowse. What was not certain, she said, is how much lupus increased a woman's health risk.
To help answer this question, Clowse's team analyzed data from more than 18 million pregnancy-related hospital admissions and discharges in the United States from 2000 to 2002. The study found that slightly more than 13,500 women with systemic lupus gave birth during this time, and 44 of the women -- 0.3 percent -- died, Clowse said.
Overall, women with systemic lupus showed a more than 20-fold greater risk of pregnancy-related death, compared with women without the disease, she said. Extrapolating this observed increase in risk to the general population suggests that for every 100,000 women with systemic lupus who would deliver a baby, approximately 325 of them would die, compared with approximately 14 deaths for every 100,000 women without the disease who would give birth, Clowse said.
"We don't want these results to scare women with lupus away from getting pregnant, especially if they have a mild form of the disease," Clowse said. "But these women really must plan their pregnancies. They may need to change their medications before they get pregnant, and they really shouldn't conceive when their lupus is active."
Clowse said patients whose lupus has been dormant for at least six months before conception are at low risk for developing active systemic lupus during pregnancy and therefore are at least somewhat less likely than women whose disease is active to experience health complications.
However, all women with systemic lupus do face elevated risks for pregnancy complications, she said. In the study population, women with systemic lupus, compared to women without the disease, were nearly six times more likely to suffer from deep vein thrombosis -- a blood clot -- and 3.5 times more likely to develop sepsis, a severe illness caused by an extreme infection of the bloodstream. Many women with lupus also were anemic or had low blood platelet counts at delivery and were three times more likely to need transfusions.
Additionally, almost 37 percent of women with lupus gave birth via cesarean section -- 15 percent higher than the national average of 22 percent. Women with lupus also were 2.5 times more likely to experience preterm labor and three times more likely to develop preeclampsia, or pregnancy-related high blood pressure, than women without lupus.
Clowse said the study's results are highly suggestive and should be taken seriously within the health care community, but she added that the study did have certain limitations.
On the plus side, the study examined a large number of patients, including patients from a variety of clinical environments, and it compared pregnancy results among women with and without lupus, she said.
However, she added, the study relied on analyzing hospital admission and discharge data, rather than on analyzing individual patient records or on examining the patients themselves.
Other researchers involved in the study were Margaret Jamison, Evan Myers and Andra James.