Women with lupus or rheumatoid arthritis - two rheumatic diseases in which the immune system mistakenly attacks tissues in the body - face an increased risk of pregnancy complications, according to a new study.

Investigators Dr. Eliza F. Chakravarty of Stanford University School of Medicine in Palo Alto and colleagues say that “women with common rheumatic diseases appeared to have an increased risk of adverse outcomes of pregnancy and should undergo careful antenatal monitoring in order to minimize any consequences.”

The research team looked at data from a 2002 nationwide inpatient survey to compare rates of pregnancy complications among women in the general population and those with lupus, rheumatoid arthritis, and other conditions.

As they report in the medical journal Arthritis & Rheumatism, the researchers found that in the general population high blood pressure problems occurred in 7.8 percent of pregnancies, while 26.5 percent of deliveries were cesarean.

The corresponding rates for women with lupus were 23.2 percent and 39.4 percent.

Retarded growth of the baby in the womb occurred more than three times more often in the group with lupus than among women in general.

For women with rheumatoid arthritis, rates of hypertensive complications, premature rupture of membranes, and fetal growth retardation were slightly but significantly higher than normal.

The findings “suggest that relatively large numbers of women with these rheumatic conditions do choose to bear children and that the majority appear to have good pregnancy outcomes,” Dr. Chakravarty and her colleagues write.

SOURCE: Arthritis & Rheumatism, March 200607.