First nationwide study of pregnancy outcomes in women with rheumatic disease

Nov 20 2005

The first nationwide study of pregnancy outcomes in women with rheumatic disease confirms that they experience greater pregnancy risks and longer hospital stays than the average pregnant woman.

The findings from the Stanford University School of Medicine provide women who have these conditions with a better understanding of the risks they face if they become pregnant and underscores the need for physicians to monitor closely their care.

The author of the study, Eliza Chakravarty, MD, assistant professor of medicine (immunology and rheumatology), will present her findings Nov. 15 during a scientific poster session at the American College of Rheumatology annual scientific meeting in San Diego.

Tina Chambers, MD, professor of pediatrics at the University of California-San Diego, who was not involved in this study, said the findings fill a troubling gap in what is known about pregnant women who suffer from these autoimmune conditions. "Intuitively, you would think that it would be easy to access [such] data," she said, "but there is little to nothing in the literature about rheumatoid arthritis or lupus in pregnant women." (Chambers has collaborated with Chakravarty on other projects.)

In this study, Chakravarty aimed to see how the pregnancy outcomes for these women would compare with the outcomes for healthy women and women with diabetes. "Nobody knew these numbers," she said.

In autoimmune diseases such as lupus or rheumatoid arthritis, the immune system turns against parts of the body it is designed to protect, leading to inflammation and damage to joints. More than 2 million Americans have rheumatoid arthritis, while another 500,000 suffer from lupus. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, rheumatoid arthritis and lupus affect far more women than men, leading researchers to believe that hormonal factors may prompt their onset.

Chakravarty was able to determine the incidence of lupus and rheumatoid arthritis pregnancies by sifting through records of pregnancies and deliveries using the Nationwide Inpatient Sample, a database of hospital discharge summaries from the entire country. In 2002, the latest year in which data was available, she found that at least 4,000 of the approximately 4 million total deliveries occurred in women with lupus or rheumatoid arthritis. By comparison, about 13,000 women who delivered in 2002 had diabetes.

"Women with rheumatoid arthritis are typically somewhat older when they become pregnant," said Chakravarty. "However, even after adjusting for maternal age, they run a higher risk for adverse outcomes and generally experience longer hospital stays than other women." On average, hospital stays increased from about two days for the general population to between three and four days for the rheumatoid group.

Chakravarty's findings also show that, compared with the general population, women with lupus or rheumatoid arthritis are three times as likely to develop hypertension and one-and-one-half times as likely to have cesarean deliveries or deliver prematurely.

In a previous study, Chakravarty had gathered evidence on the effects of lupus in 63 pregnant women at Stanford. Her results revealed that more than half of the deliveries were premature, and one-fifth suffered from pre-eclampsia - a condition characterized by a sharp rise in blood pressure during the third trimester of pregnancy. Her new study shows that the problems suffered by the women at Stanford are similar to what women experience nationwide.

"Until now, all studies have been reported from a single center," said Chakravarty. "I wanted to know, is this what happens across the country?"