Impact of Pregnancy on Inflammatory Arthritis
Pregnancy and Arthritis
During pregnancy, women with inflammatory arthritis usually experience disease improvement or even remission, while a disease flare regularly occurs within 3 to 4 months after delivery. A study featured in the July 2006 issue of Arthritis & Rheumatism sheds light on this widely reported yet little understood phenomenon.
Prenatal diagnostic tests have recently established that fetal cells and cell-free DNA routinely flow into the mother's bloodstream during normal pregnancy. On the strength of these findings, researchers in Seattle, Washington, supported in part by a grant from the Washington Women's Foundation and by grants from the National Institutes of Health, set out to investigate whether changes in serum fetal DNA levels correlate with changes in arthritis activity during and after pregnancy. They conducted a study on 25 pregnant women with inflammatory arthritis.
Ranging in age from 23 to 43, 17 of the women were classified as having adult-onset rheumatoid arthritis (RA) and 6 were classified as having juvenile idiopathic arthritis (JIA). Of the subjects, 24 had active disease in the 6 months prior to pregnancy, with one experiencing RA onset in her first trimester. 7 of the women were in their first pregnancy, 7 were in their second pregnancy, and 11 had been pregnant at least twice before. None of the patients took a disease-modifying antirheumatic drug during pregnancy, and patients taking prednisone took no more than 10 milligrams per day, with one exception. All pregnancies resulted in a single live birth.
Samples of peripheral venous blood were taken from all subjects, most 3 times or more during the course of pregnancy, as well as postpartum, within 3 months of delivery. Levels of cell-free fetal DNA were measured using real-time quantitative polymerase chain reaction targeting the fetus-specific genetic markers. Women were evaluated for changes in disease activity in each trimester and 3 to 4 months after giving birth.
During pregnancy, 21 of the 25 women